Sri Lanka

In antiquity, Sri Lanka was known to travellers by a variety of names. According to the Mahāvaṃsa, the legendary Prince Vijaya named the island Tambapaṇṇĩ ("copper-red hands" or "copper-red earth"), because his followers' hands were reddened by the red soil of the area where he landed. In Hindu mythology, the term Lankā ("Island") appears but it is unknown whether it refers to the island. The Tamil term Eelam (Tamil: ஈழம், romanised: īḻam) was used to designate the whole island in Sangam literature. The island was known under Chola rule as Mummudi Cholamandalam ("realm of the three crowned Cholas").

Ancient Greek geographers called it Taprobanā (Ancient Greek: Ταπροβανᾶ) or Taprobanē (Ταπροβανῆ) from the word Tambapanni. The Arabs and Persians referred to it as Sarandīb (the origin of the word "serendipity") from Sanskrit Siṃhaladvīpaḥ. Ceilão, the name given to Sri Lanka by the Portuguese when they arrived in 1505, was transliterated into English as Ceylon. As a British crown colony, the island was known as Ceylon; it achieved independence as the Dominion of Ceylon in 1948.

The country is now known in Sinhala as Śrī Laṅkā (Sinhala: ශ්‍රී ලංකා) and in Tamil as Ilaṅkai (Tamil: இலங்கை, IPA: [iˈlaŋɡaɪ]). In 1972, its formal name was changed to "Free, Sovereign and Independent Republic of Sri Lanka". Later, on 7 September 1978, it was changed to the "Democratic Socialist Republic of Sri Lanka". As the name Ceylon still appears in the names of a number of organisations, the Sri Lankan government announced in 2011 a plan to rename all those over which it has authority.

=== Prehistory ===

The pre-history of Sri Lanka goes back 125,000 years and possibly even as far back as 500,000 years. The era spans the Palaeolithic, Mesolithic, and early Iron Ages. Among the Palaeolithic human settlements discovered in Sri Lanka, Pahiyangala (37,000 BP), named after the Chinese traveller monk Faxian; Batadombalena (28,500 BP); and Belilena (12,000 BP) are the most important. In these caves, archaeologists have found the remains of anatomically modern humans which they have named Balangoda Man, and other evidence suggesting that they may have engaged in agriculture and kept domestic dogs for driving game.

The earliest inhabitants of Sri Lanka were likely ancestors of the Vedda people, an indigenous people numbering approximately 2,500 living in modern-day Sri Lanka.

During the protohistoric period (1000–500 BCE) Sri Lanka was culturally united with southern India, and shared the same megalithic burials, pottery, iron technology, farming techniques and megalithic graffiti. This cultural complex spread from southern India along with Dravidian clans such as the Velir, prior to the migration of Prakrit speakers.

One of the first written references to the island is found in the Indian epic Ramayana, which provides details of a kingdom named Lanka that was created by the divine sculptor Vishvakarma for Kubera, the God of Wealth. It is said that Kubera was overthrown by his rakshasa stepbrother, Ravana.

According to the Mahāvaṃsa, a Pāḷi chronicle written in the 5th century CE, the original inhabitants of Sri Lanka are said to be the Yakshas and Nagas. Sinhalese history traditionally starts in 543 BCE with the arrival of Prince Vijaya, a semi-legendary prince who sailed with 700 followers to Sri Lanka, after being expelled from Vanga kingdom (present-day Bengal). He established the Kingdom of Tambapanni, near modern-day Mannar. Vijaya (Singha) is the first of the approximately 189 monarchs of Sri Lanka described in chronicles such as the Dīpavaṃsa, Mahāvaṃsa, Cūḷavaṃsa, and Rājāvaliya.

Once Prakrit speakers had attained dominance on the island, the Mahāvaṃsa further recounts the later migration of royal brides and service castes from the Tamil Pandya kingdom to the Anuradhapura kingdom in the early historic period.

The Anuradhapura period (377 BCE – 1017 CE) began with the establishment of the Anuradhapura kingdom in 380 BCE during the reign of Pandukabhaya. Thereafter, Anuradhapura served as the capital city of the country for nearly 1,400 years. Ancient Sri Lankans excelled at building certain types of structures such as tanks, dagobas and palaces. Society underwent a major transformation during the reign of Devanampiya Tissa, with the arrival of Buddhism from India. In 250 BCE, Mahinda, a bhikkhu and the son of the Mauryan Emperor Ashoka arrived in Mihintale carrying the message of Buddhism. His mission won over the monarch, who embraced the faith and propagated it throughout the Sinhalese population.

Succeeding kingdoms of Sri Lanka would maintain many Buddhist schools and monasteries and support the propagation of Buddhism into other countries in Southeast Asia. Sri Lankan Bhikkhus studied in India's famous ancient Buddhist University of Nalanda, which was destroyed by Bakhtiyar Khalji. It is probable that many of the scriptures from Nalanda are preserved in Sri Lanka's many monasteries and that the written form of the Tripiṭaka, including Sinhalese Buddhist literature, were part of the University of Nalanda. In 245 BCE, bhikkhunī Sanghamitta arrived with the Jaya Sri Maha Bodhi tree, which is considered to be a sapling from the historical Bodhi Tree under which Gautama Buddha became enlightened. It is considered the oldest human-planted tree (with a continuous historical record) in the world. (Bodhivaṃsa)

Sri Lanka experienced the first of many foreign invasions during the reign of Suratissa, who was defeated by two horse traders named Sena and Guttika from South India. The next invasion came immediately in 205 BCE by a Chola named Elara, who overthrew Asela and ruled the country for 44 years. Dutugamunu, the eldest son of the southern regional sub-king, Kavan Tissa, defeated Elara in the Battle of Vijithapura. During its two and a half millennia of existence, the Sinhala kingdom was invaded at least eight times by neighbouring South Indian dynasties such as the Chola, Pandya, and Pallava. There also were incursions by the kingdoms of Kalinga (modern Odisha) and from the Malay Peninsula as well.

The Fourth Theravāda Council was held at the Anuradhapura Maha Viharaya in Sri Lanka under the patronage of Valagamba in 25 BCE. The council was held in response to a year in which the harvests in Sri Lanka were particularly poor and many Buddhist monks subsequently died of starvation. Because the Pali Canon was at that time oral literature maintained in several recensions by dhammabhāṇakas (dharma reciters), the surviving monks recognised the danger of not writing it down so that even if some of the monks whose duty it was to study and remember parts of the Canon for later generations died, the teachings would not be lost. After the council, palm-leaf manuscripts containing the completed Canon were taken to other countries such as Burma, Thailand, Cambodia and Laos.

Sri Lanka was the first Asian country known to have a female ruler: Anula of Anuradhapura (r. 47–42 BCE). Sri Lankan monarchs undertook some remarkable construction projects such as Sigiriya, the so-called "Fortress in the Sky", built during the reign of Kashyapa I, who ruled between 477 and 495. The Sigiriya rock fortress is surrounded by an extensive network of ramparts and moats. Inside this protective enclosure were gardens, ponds, pavilions, palaces and other structures.

In 993 CE, the invasion of Chola emperor Rajaraja I forced the then Sinhalese ruler Mahinda V to flee to the southern part of Sri Lanka. Taking advantage of this situation, Rajendra I, son of Rajaraja I, launched a large invasion in 1017. Mahinda V was captured and taken to India, and the Cholas sacked the city of Anuradhapura causing the fall of Anuradhapura kingdom. Subsequently, they moved the capital to Polonnaruwa.

Following a 17-year-long campaign, Vijayabahu I successfully drove the Chola out of Sri Lanka in 1070, reuniting the country for the first time in over a century. Upon his request, ordained monks were sent from Burma to Sri Lanka to re-establish Buddhism, which had almost disappeared from the country during the Chola reign. During the mediaeval period, Sri Lanka was divided into three sub-territories, namely, Ruhunu, Pihiti and Maya.

Sri Lanka's irrigation system was extensively expanded during the reign of Parākramabāhu the Great (1153–1186). This period is considered as a time when Sri Lanka was at the height of its power. He built 1,470 reservoirs – the highest number by any ruler in Sri Lanka's history – repaired 165 dams, 3,910 canals, 163 major reservoirs, and 2,376 mini-reservoirs. His most famous construction is the Parakrama Samudra, the largest irrigation project of mediaeval Sri Lanka. Parākramabāhu's reign is memorable for two major campaigns – in the south of India as part of a Pandyan war of succession, and a punitive strike against the kings of Ramanna (Burma) for various perceived insults to Sri Lanka.

After his demise, Sri Lanka gradually decayed in power. In 1215, Kalinga Magha, an invader with uncertain origins, identified as the founder of the Jaffna kingdom, invaded and captured the Kingdom of Polonnaruwa. He sailed from Kalinga 690 nautical miles on 100 large ships with a 24,000 strong army. Unlike previous invaders, he looted, ransacked and destroyed everything in the ancient Anuradhapura and Polonnaruwa Kingdoms beyond recovery. His priorities in ruling were to extract as much as possible from the land and overturn as many of the traditions of Rajarata as possible. His reign saw the massive migration of native Sinhalese people to the south and west of Sri Lanka, and into the mountainous interior, in a bid to escape his power.

Sri Lanka never really recovered from the effects of Kalinga Magha's invasion. King Vijayabâhu III, who led the resistance, brought the kingdom to Dambadeniya. The north, in the meanwhile, eventually evolved into the Jaffna kingdom. The Jaffna kingdom never came under the rule of any kingdom of the south except on one occasion; in 1450, following the conquest led by king Parâkramabâhu VI's adopted son, Prince Sapumal. He ruled the North from 1450 to 1467 CE.

The next three centuries starting from 1215 were marked by kaleidoscopically shifting collections of capitals in south and central Sri Lanka, including Dambadeniya, Yapahuwa, Gampola, Raigama, Kotte, Sitawaka, and finally, Kandy. In 1247, the Malay kingdom of Tambralinga which was a vassal of Sri Vijaya led by their king Chandrabhanu briefly invaded Sri Lanka from Insular Southeast Asia. They were then expelled by the South Indian Pandyan dynasty. However, this temporary invasion reinforced the steady flow of the presence of various Austronesian merchant ethnic groups, from Sumatrans (Indonesia) to Lucoes (Philippines) into Sri Lanka which occurred since 200 BCE. Chinese admiral Zheng He and his naval expeditionary force landed at Galle, Sri Lanka in 1409 and got into battle with the local king Vira Alakesvara of Gampola. Zheng He captured King Vira Alakesvara and later released him. Zheng He erected the Galle Trilingual Inscription, a stone tablet at Galle written in three languages (Chinese, Tamil, and Persian), to commemorate his visit. The stele was discovered by S. H. Thomlin at Galle in 1911 and is now preserved in the Colombo National Museum.

The early modern period of Sri Lanka begins with the arrival of Portuguese soldier and explorer Lourenço de Almeida, the son of Francisco de Almeida, in 1505. In 1517, the Portuguese built a fort at the port city of Colombo and gradually extended their control over the coastal areas. In 1592, after decades of intermittent warfare with the Portuguese, Vimaladharmasuriya I moved his kingdom to the inland city of Kandy, a location he thought more secure from attack. In 1619, succumbing to attacks by the Portuguese, the independent existence of the Jaffna kingdom came to an end.

During the reign of the Rajasinha II, Dutch explorers arrived on the island. In 1638, the king signed a treaty with the Dutch East India Company to get rid of the Portuguese who ruled most of the coastal areas. The following Dutch–Portuguese War resulted in a Dutch victory, with Colombo falling into Dutch hands by 1656. The Dutch remained in the areas they had captured, thereby violating the treaty they had signed in 1638. The Burgher people, a distinct ethnic group, emerged as a result of intermingling between the Dutch and native Sri Lankans in this period.

The Kingdom of Kandy was the last independent monarchy of Sri Lanka. In 1595, Vimaladharmasurya brought the sacred Tooth Relic—the traditional symbol of royal and religious authority amongst the Sinhalese—to Kandy and built the Temple of the Tooth. In spite of on-going intermittent warfare with Europeans, the kingdom survived. Later, a crisis of succession emerged in Kandy upon king Vira Narendra Sinha 's death in 1739. He was married to a Telugu-speaking Nayakkar princess from South India (Madurai) and was childless by her.

Eventually, with the support of bhikkhu Weliwita Sarankara and ignoring the right of "Unambuwe Bandara", the crown passed to the brother of one of Narendrasinha's princesses, overlooking Narendrasinha's own son by a Sinhalese concubine. The new king was crowned Sri Vijaya Rajasinha later that year. Kings of the Nayakkar dynasty launched several attacks on Dutch controlled areas, which proved to be unsuccessful.

During the French Revolutionary Wars, fearing that French control of the Netherlands might deliver Sri Lanka to the French, the British Empire occupied the coastal areas of the island (which they called the colony of British Ceylon) with little difficulty in 1796. Two years later, in 1798, Sri Rajadhi Rajasinha, third of the four Nayakkar kings of Sri Lanka, died of a fever. Following his death, a nephew of Rajadhi Rajasinha, eighteen-year-old Kannasamy, was crowned. The young king, now named Sri Vikrama Rajasinha, faced a British invasion in 1803 but successfully retaliated. The First Kandyan War ended in a stalemate.

By then the entire coastal area was under the British East India Company as a result of the Treaty of Amiens. On 14 February 1815, Kandy was occupied by the British in the Second Kandyan War, ending Sri Lanka's independence. Sri Vikrama Rajasinha, the last native monarch of Sri Lanka, was exiled to India. The Kandyan Convention formally ceded the entire country to the British Empire. Attempts by Sri Lankan noblemen to undermine British power in 1818 during the Uva Rebellion were thwarted by Governor Robert Brownrigg.

The beginning of the modern period of Sri Lanka is marked by the Colebrooke–Cameron reforms of 1833. They introduced a utilitarian and liberal political culture to the country based on the rule of law and amalgamated the Kandyan and maritime provinces as a single unit of government. An executive council and a legislative council were established, later becoming the foundation of a representative legislature. By this time, experiments with coffee plantations were largely successful.

Soon, coffee became the primary commodity export of Sri Lanka. Falling coffee prices as a result of the depression of 1847 stalled economic development and prompted the governor to introduce a series of taxes on firearms, dogs, shops, boats, etc., and to reintroduce a form of rajakariya, requiring six days free labour on roads or payment of a cash equivalent. These harsh measures antagonised the locals, and another rebellion broke out in 1848. A devastating leaf disease, Hemileia vastatrix, struck the coffee plantations in 1869, destroying the entire industry within fifteen years. The British quickly found a replacement: abandoning coffee, they began cultivating tea instead. Tea production in Sri Lanka thrived in the following decades. Large-scale rubber plantations began in the early 20th century.

By the end of the 19th century, a new educated social class transcending race and caste arose through British attempts to staff the Ceylon Civil Service and the legal, educational, engineering, and medical professions with natives. New leaders represented the various ethnic groups of the population in the Ceylon Legislative Council on a communal basis. Buddhist and Hindu revivalists reacted against Christian missionary activities. The first two decades in the 20th century are noted by the unique harmony among Sinhalese and Tamil political leadership, which has since been lost.

The 1906 malaria outbreak in Ceylon actually started in the early 1900s, but the first case was documented in 1906.

In 1919, major Sinhalese and Tamil political organisations united to form the Ceylon National Congress, under the leadership of Ponnambalam Arunachalam, pressing colonial masters for more constitutional reforms. But without massive popular support, and with the governor's encouragement for "communal representation" by creating a "Colombo seat" that dangled between Sinhalese and Tamils, the Congress lost momentum towards the mid-1920s.

The Donoughmore reforms of 1931 repudiated the communal representation and introduced universal adult franchise (the franchise stood at 4% before the reforms). This step was strongly criticised by the Tamil political leadership, who realised that they would be reduced to a minority in the newly created State Council of Ceylon, which succeeded the legislative council. In 1937, Tamil leader G. G. Ponnambalam demanded a 50–50 representation (50% for the Sinhalese and 50% for other ethnic groups) in the State Council. However, this demand was not met by the Soulbury reforms of 1944–45.

The Soulbury constitution ushered in dominion status, with independence proclaimed on 4 February 1948. D. S. Senanayake became the first Prime Minister of Ceylon. Prominent Tamil leaders including Ponnambalam and Arunachalam Mahadeva joined his cabinet. The British Royal Navy remained stationed at Trincomalee until 1956. A countrywide popular demonstration against withdrawal of the rice rations resulted in the resignation of prime minister Dudley Senanayake.

S. W. R. D. Bandaranaike was elected prime minister in 1956. His three-year rule had a profound influence through his self-proclaimed role of "defender of the besieged Sinhalese culture". He introduced the controversial Sinhala Only Act, recognising Sinhala as the only official language of the government. Although partially reversed in 1958, the bill posed a grave concern for the Tamil community, which perceived in it a threat to their language and culture.

The Federal Party (FP) launched a movement of non-violent resistance (satyagraha) against the bill, which prompted Bandaranaike to reach an agreement (Bandaranaike–Chelvanayakam Pact) with S. J. V. Chelvanayakam, leader of the FP, to resolve the looming ethnic conflict. The pact proved ineffective in the face of ongoing protests by opposition and the Buddhist clergy. The bill, together with various government colonisation schemes, contributed much towards the political rancour between Sinhalese and Tamil political leaders. Bandaranaike was assassinated by an extremist Buddhist monk in 1959.

Sirimavo Bandaranaike, the widow of Bandaranaike, took office as prime minister in 1960, and withstood an attempted coup d'état in 1962. During her second term as prime minister, the government instituted socialist economic policies, strengthening ties with the Soviet Union and China, while promoting a policy of non-alignment. In 1971, Ceylon experienced a Marxist insurrection, which was quickly suppressed. In 1972, the country became a republic named Sri Lanka, repudiating its dominion status. Prolonged minority grievances and the use of communal emotionalism as an election campaign weapon by both Sinhalese and Tamil leaders abetted a fledgling Tamil militancy in the north during the 1970s. The policy of standardisation by the Sirimavo government to rectify disparities created in university enrolment, which was in essence an affirmative action to assist geographically disadvantaged students to obtain tertiary education, resulted in reducing the proportion of Tamil students at university level and acted as the immediate catalyst for the rise of militancy. The assassination of Jaffna Mayor Alfred Duraiyappah in 1975 by the Liberation Tigers of Tamil Eelam (LTTE) marked a crisis point.

The government of J. R. Jayawardene swept to power in 1977, defeating the United Front government. Jayawardene introduced a new constitution, together with a free-market economy and a powerful executive presidency modelled after that of France. It made Sri Lanka the first South Asian country to liberalise its economy. Beginning in 1983, ethnic tensions were manifested in an on-and-off insurgency against the government by the LTTE. An LTTE attack on 13 soldiers resulted in the start of a civil war, and in response anti-Tamil race riots took place, allegedly backed by Sinhalese hard-line ministers, which resulted in more than 150,000 Tamil civilians fleeing the island, seeking asylum in other countries.

Lapses in foreign policy resulted in India strengthening the Tigers by providing arms and training. In 1987, the Indo-Sri Lanka Accord was signed and the Indian Peace Keeping Force (IPKF) was deployed in northern Sri Lanka to stabilise the region by neutralising the LTTE. The same year, the JVP launched its second insurrection in Southern Sri Lanka, necessitating redeployment of the IPKF in 1990. In October 1990, the LTTE expelled Sri Lankan Moors (Muslims by religion) from northern Sri Lanka. In 2002, the Sri Lankan government and LTTE signed a Norwegian-mediated ceasefire agreement.

The 2004 Asian tsunami killed over 30,000 and displaced over 500,000 people in Sri Lanka.

From 1985 to 2006, the Sri Lankan government and Tamil insurgents held four rounds of peace talks without success. Both LTTE and the government resumed fighting in 2006, and the government officially backed out of the ceasefire in 2008. In 2009, under the Presidency of Mahinda Rajapaksa, the Sri Lanka Armed Forces defeated the LTTE, bringing an end to the 26 year long civil war on 19 May 2009, and re-established control of the entire country by the Sri Lankan Government. Overall, between 60,000 and 100,000 people were killed during the course of the 26 year long conflict.

2019 Sri Lanka Easter bombings carried out by the terrorist group National Thowheeth Jama'ath on 21 April 2019 killed 261 people. On 26 April 2019 an anti terrorist operation was carried out against the National Thowheeth Jama'ath by the Sri Lanka Army with the operation being successful and National Thowheeth Jama'ath's insurgency ending.

Economic troubles in Sri Lanka began in 2019, when a severe economic crisis occurred caused by rapidly increasing foreign debt, massive government budget deficits due to tax cuts, falling foreign remittances, a food crisis caused by mandatory organic farming along with a ban on chemical fertilisers, and a multitude of other factors. The Sri Lankan Government officially declared the ongoing crisis to be the worst economic crisis in the country in 73 years. In August 2021, a food emergency was declared. In June 2022, Prime Minister Ranil Wickremesinghe declared the collapse of the Sri Lankan economy in parliament. The crisis resulted in Sri Lanka defaulting on its $51 billion sovereign debt for the first time in its history, along with double-digit inflation, a crippling energy crisis that led to approximately 15 hour power cuts, severe fuel shortages leading to the suspension of fuel to all non-essential vehicles, and more such economic disorder. Due to the crisis, massive street protests erupted all over the country, with protesters demanding the resignation of the President Gotabaya Rajapaksa. The protests culminated with the storming and siege of the President's House on 9 July 2022, and resulted in President Gotabaya Rajapaksa fleeing to Singapore and later emailing his resignation to parliament, formally announcing his resignation and making him the first Sri Lankan president to resign in the middle of his term. On the same day the President's House was stormed, protesters besieged and stormed the private residence of the prime minister and burnt it down.

After Parliament elected the new president as Ranil Wickremesinghe on 20 July 2022, Wickremesinghe took oath as the ninth President of Sri Lanka. He implemented various economic reforms in efforts to stabilise Sri Lanka's economy, which has shown slight improvement since. On 23 September 2024, Anura Kumara Dissanayake was sworn in as Sri Lanka's new president after winning the presidential election as a left-wing candidate. On 14 November 2024, President Anura Kumara Dissanayake's National People's Power (NPP), a left-leaning alliance, received a two-thirds majority in parliament in Sri Lankan parliamentary election.

Sri Lanka, an island in South Asia, lies on the Indian Plate, a major tectonic plate that was formerly part of the Indo-Australian Plate. It is in the Indian Ocean southwest of the Bay of Bengal, between latitudes 5° and 10° N, and longitudes 79° and 82° E. Sri Lanka is separated from the mainland portion of the Indian subcontinent by the Gulf of Mannar and Palk Strait. According to Hindu mythology, a land bridge existed between the Indian mainland and Sri Lanka. It now amounts to only a chain of limestone shoals remaining above sea level. Legends claim that it was passable on foot up to 1480 CE, until cyclones deepened the channel. Portions are still as shallow as 1 metre (3 ft), hindering navigation. The island consists mostly of flat to rolling coastal plains, with mountains rising only in the south-central part. The highest point is Pidurutalagala, reaching 2,524 metres (8,281 ft) above sea level.

Sri Lanka has 103 rivers. The longest of these is the Mahaweli River, extending 335 kilometres (208 mi). These waterways give rise to 51 natural waterfalls of 10 metres (33 ft) or more. The highest is Bambarakanda Falls, with a height of 263 metres (863 ft). Sri Lanka's coastline is 1,585 km (985 mi) long. Sri Lanka claims an exclusive economic zone extending 200 nautical miles, which is approximately 6.7 times Sri Lanka's land area. The coastline and adjacent waters support highly productive marine ecosystems such as fringing coral reefs and shallow beds of coastal and estuarine seagrasses.

Sri Lanka has 45 estuaries and 40 lagoons. Sri Lanka's mangrove ecosystem spans over 7,000 hectares and played a vital role in buffering the force of the waves in the 2004 Indian Ocean tsunami. The island is rich in minerals such as ilmenite, feldspar, graphite, silica, kaolin, mica and thorium. Existence of petroleum and gas in the Gulf of Mannar has also been confirmed, and the extraction of recoverable quantities is underway.

The climate is tropical and warm because of moderating effects of ocean winds. Mean temperatures range from 17 °C (62.6 °F) in the Central Highlands, where frost may occur for several days in the winter, to a maximum of 33 °C (91.4 °F) in low-altitude areas. Average yearly temperatures range from 28 °C (82.4 °F) to nearly 31 °C (87.8 °F). Day and night temperatures may vary by 14 °C (25 °F) to 18 °C (32 °F).

The rainfall pattern is influenced by monsoon winds from the Indian Ocean and Bay of Bengal. The "wet zone" and some of the windward slopes of the central highlands receive up to 2,500 millimetres (98.4 in) of rain each year, but the leeward slopes in the east and northeast receive little rain. Most of the east, southeast, and northern parts of Sri Lanka constitute the "dry zone", which receives between 1,200 and 1,900 mm (47 and 75 in) of rain annually.

The arid northwest and southeast coasts receive the least rain at 800 to 1,200 mm (31 to 47 in) per year. Periodic squalls occur and sometimes tropical cyclones bring overcast skies and rains to the southwest, northeast, and eastern parts of the island. Humidity is typically higher in the southwest and mountainous areas and depends on the seasonal patterns of rainfall. An increase in average rainfall coupled with heavier rainfall events has resulted in recurrent flooding and related damages to infrastructure, utility supply and the urban economy.

The Western Ghats of India and Sri Lanka were included among the first 18 global biodiversity hotspots due to high levels of species endemism. The number of biodiversity hotspots has now increased to 34. Sri Lanka has the highest biodiversity per unit area among Asian countries for flowering plants and all vertebrate groups except birds. A remarkably high proportion of the species among its flora and fauna, 27% of the 3,210 flowering plants and 22% of the mammals, are endemic. Sri Lanka supports a rich avifauna of that stands at 453 species and this includes 240 species of birds that are known to breed in the country. 33 species are accepted by some ornithologists as endemic while some ornithologists consider only 27 are endemic and the remaining six are considered as proposed endemics. Sri Lanka's protected areas are administered by two government bodies: The Department of Forest Conservation and the Department of Wildlife Conservation. Department of Wildlife Conservation administers 61 wildlife sanctuaries, 22 national parks, four nature reserves, three strict nature reserves, and one jungle corridor; while Department of Forest Conservation oversees 65 conservation forests and one national heritage wilderness area. 26.5% of the country's land area is legally protected. This is a higher percentage of protected areas when compared to the rest of Asia.

Sri Lanka contains four terrestrial ecoregions: Sri Lanka lowland rain forests, Sri Lanka montane rain forests, Sri Lanka dry-zone dry evergreen forests, and Deccan thorn scrub forests. Flowering acacias flourish on the arid Jaffna Peninsula. Among the trees of the dry-land forests are valuable species such as satinwood, ebony, ironwood, mahogany and teak. The wet zone is a tropical evergreen forest with tall trees, broad foliage, and a dense undergrowth of vines and creepers. Subtropical evergreen forests resembling those of temperate climates flourish in the higher altitudes.

Yala National Park in the southeast protects herds of elephant, deer, and peacocks. The Wilpattu National Park in the northwest, the largest national park, preserves the habitats of many water birds such as storks, pelicans, ibis, and spoonbills. The island has four biosphere reserves: Bundala, Hurulu Forest Reserve, the Kanneliya-Dediyagala-Nakiyadeniya, and Sinharaja. Sinharaja is home to 26 endemic birds and 20 rainforest species, including the elusive red-faced malkoha, the green-billed coucal and the Sri Lanka blue magpie. The untapped genetic potential of Sinharaja flora is enormous. Of the 211 woody trees and lianas within the reserve, 139 (66%) are endemic. The total vegetation density, including trees, shrubs, herbs, and seedlings, has been estimated at 240,000 individuals per hectare. The Minneriya National Park borders the Minneriya Tank, which is an important source of water for elephants inhabiting the surrounding forests. Dubbed "The Gathering", the congregation of elephants can be seen on the tank-bed in the late dry season (August to October) as the surrounding water sources steadily disappear. The park also encompasses a range of micro-habitats which include classic dry zone tropical monsoonal evergreen forest, thick stands of giant bamboo, hilly pastures (patanas), and grasslands (talawas).

During the Mahaweli Programme of the 1970s and 1980s in northern Sri Lanka, the government set aside four areas of land totalling 1,900 km2 (730 sq mi) as national parks. Statistics of Sri Lanka's forest cover show rapid deforestation from 1956 to 2010. In 1956, 44.2 percent of the country's land area had forest cover. Forest cover depleted rapidly in recent decades; 29.6 percent in 1999, 28.7 percent in 2010.

Sri Lanka is a democratic republic and a unitary state which is governed by a semi-presidential system. Sri Lanka is the oldest democracy in Asia. Most provisions of the constitution can be amended by a two-thirds majority in parliament. The amendment of certain fundamental features, including clauses on national symbols, religion, term limits, the reference to Sri Lanka as a unitary state, and the entrenchment mechanism itself, requires both a two-thirds majority in Parliament and approval in a nationwide referendum. The Constitution of Sri Lanka officially declares it to be a socialist state.

In common with many democracies, the Sri Lankan government has three branches:

Executive: The President of Sri Lanka is the head of state; the commander in chief of the armed forces; chief executive, and is popularly elected for a five-year term. The president heads the cabinet and appoints ministers from elected members of parliament. The president is immune from legal proceedings while in the office with respect to any acts done or omitted to be done by him or her in either an official or private capacity. Following the passage of the 19th amendment to the constitution in 2015, the president has two terms, which previously stood at no term limit.

Legislative: The Parliament of Sri Lanka is a unicameral 225-member legislature with 196 members elected from 22 multi-seat constituencies and 29 elected by proportional representation. Members are elected by universal suffrage for a five-year term. The president may summon, suspend, or end a legislative session and dissolve Parliament anytime after four and a half years. The parliament reserves the power to make all laws. The president's deputy and head of government, the prime minister, leads the ruling party in parliament and shares many executive responsibilities, mainly in domestic affairs.

Judicial: Sri Lanka's judiciary consists of a Supreme Court—the highest and final superior court of record, a Court of Appeal, High Courts, and a number of subordinate courts. The highly complex legal system reflects diverse cultural influences. Criminal law is based almost entirely on British law. Basic civil law derives from Roman-Dutch law. Laws pertaining to marriage, divorce, and inheritance are communal. Because of ancient customary practices and religion, the Sinhala customary law (Kandyan law), the Thesavalamai, and Sharia law are followed in special cases. The president appoints judges to the Supreme Court, the Court of Appeal, and the High Courts. A judicial service commission, composed of the chief justice and two Supreme Court judges, appoints, transfers, and dismisses lower court judges.

The current political culture in Sri Lanka is a contest between two rival coalitions led by the centre-left and progressive United People's Freedom Alliance (UPFA), an offspring of Sri Lanka Freedom Party (SLFP), and the comparatively right-wing and pro-capitalist United National Party (UNP). After 2018, two major political parties split from these two parties: The Samagi Jana Balawegaya split from the UNP, and the Sri Lanka Podujana Peramuna split from the UPFA. The third wing party Janatha Vimukthi Peramuna has gained popularity since 2022.

Sri Lanka is essentially a multi-party democracy with many smaller Buddhist, socialist, and Tamil nationalist political parties. As of July 2011, the number of registered political parties in the country is 67. Of these, the Lanka Sama Samaja Party (LSSP), established in 1935, is the oldest.

The UNP, established by D. S. Senanayake in 1946, was until recently the largest single political party. It is the only political group which had representation in all parliaments since independence. SLFP was founded by S. W. R. D. Bandaranaike in July 1951. SLFP registered its first victory in 1956, defeating the ruling UNP in the 1956 Parliamentary election. Following the parliamentary election in July 1960, Sirimavo Bandaranaike became the prime minister and the world's first elected female head of government.

G. G. Ponnambalam, the Tamil nationalist counterpart of S. W. R. D. Bandaranaike, founded the All Ceylon Tamil Congress (ACTC) in 1944. Objecting to Ponnambalam's cooperation with D. S. Senanayake, a dissident group led by S.J.V. Chelvanayakam broke away in 1949 and formed the Illankai Tamil Arasu Kachchi (ITAK), also known as the Federal Party, becoming the main Tamil political party in Sri Lanka for the next two decades. The Federal Party advocated a more aggressive stance toward the Sinhalese. With the constitutional reforms of 1972, the ACTC and ITAK created the Tamil United Front (later Tamil United Liberation Front). Following a period of turbulence as Tamil militants rose to power in the late 1970s, these Tamil political parties were succeeded in October 2001 by the Tamil National Alliance. Janatha Vimukthi Peramuna, a Marxist–Leninist political party founded by Rohana Wijeweera in 1965, serves as a third force in the current political context. It endorses leftist policies which are more radical than the traditionalist leftist politics of the LSSP and the Communist Party. Founded in 1981, the Sri Lanka Muslim Congress is the largest Muslim political party in Sri Lanka.

President Mahinda Rajapaksa lost the 2015 presidential elections, ending his ten-year presidency. However, his successor as Sri Lankan President, Maithripala Sirisena, decided not to seek re-election in 2019. The Rajapaksa family regained power in November 2019 presidential elections when Mahinda's younger brother and former wartime defence chief Gotabaya Rajapaksa won the election, and he was later sworn in as the new president of Sri Lanka. Their firm grip of power was consolidated in the parliamentary elections in August 2020. The family's political party, Sri Lanka People's Front (known by its Sinhala initials SLPP), obtained a landslide victory and a clear majority in the parliament. Five members of the Rajapaksa family won seats in the new parliament. Former president Mahinda Rajapaksa became the new prime minister.

In 2022, a political crisis started due to the power struggle between President Gotabaya Rajapaksa and the Parliament of Sri Lanka. The crisis was fuelled by anti-government protests and demonstrations by the public and also due to the worsening economy of Sri Lanka since 2019. The anti-government sentiment across various parts of Sri Lanka has triggered unprecedented political instability, creating shockwaves in the political arena.

On 20 July 2022, Ranil Wickremesinghe was elected as the ninth President via a parliamentarian election. President Ranil Wickremesinghe was defeated by left-leaning Anura Kumara Dissanayake in 2024 presidential elections.

For administrative purposes, Sri Lanka is divided into nine provinces and twenty-five districts.

Provinces in Sri Lanka have existed since the 19th century, but they had no legal status until 1987 when the 13th Amendment of the 1978 constitution established provincial councils after several decades of increasing demand for a decentralisation of the government. Each provincial council is an autonomous body not under the authority of any ministry. Some of its functions had been undertaken by central government ministries, departments, corporations, and statutory authorities, but authority over land and police is not as a rule given to provincial councils. Between 1989 and 2006, the Northern and Eastern provinces were temporarily merged to form the North-East Province. Prior to 1987, all administrative tasks for the provinces were handled by a district-based civil service which had been in place since colonial times. Now each province is administered by a directly elected provincial council:

Each district is administered under a district secretariat. The districts are further subdivided into 256 divisional secretariats, and these to approximately 14,008 Grama Niladhari divisions. The districts are known in Sinhala as disa and in Tamil as māwaddam. Originally, a disa (usually rendered into English as Dissavony) was a duchy, notably Matale and Uva.

There are three other types of local authorities: municipal councils (18), urban councils (13) and pradeshiya sabha, also called pradesha sabhai (256). Local authorities were originally based on feudal counties named korale and rata, and were formerly known as "D.R.O. divisions" after the divisional revenue officer. Later, the D.R.O.s became "assistant government agents", and the divisions were known as "A.G.A. divisions". These divisional secretariats are currently administered by a divisional secretary.

Sri Lanka is a founding member of the Non-Aligned Movement (NAM). While ensuring that it maintains its independence, Sri Lanka has cultivated relations with India. Sri Lanka became a member of the United Nations in 1955. Today, it is also a member of the Commonwealth, the SAARC, the World Bank, the International Monetary Fund, the Asian Development Bank, and the Colombo Plan.

The United National Party has traditionally favoured links with the West, while the Sri Lanka Freedom Party has favoured links with the East. Sri Lankan Finance Minister J. R. Jayewardene, together with then Australian Foreign Minister Sir Percy Spencer, proposed the Colombo Plan at the Commonwealth Foreign Minister's Conference held in Colombo in 1950. At the San Francisco Peace Conference in 1951, while many countries were reluctant, Sri Lanka argued for a free Japan and refused to accept payment of reparations for World War II damage because it believed it would harm Japan's economy. Sri Lanka-China relations started as soon as the People's Republic of China was formed in 1949. The two countries signed an important Rubber-Rice Pact in 1952. Sri Lanka played a vital role at the Asian–African Conference in 1955, which was an important step in the crystallisation of the NAM.

The Bandaranaike government of 1956 significantly changed the pro-western policies set by the previous UNP government. It recognised Cuba under Fidel Castro in 1959. Shortly afterward, Cuba's revolutionary Che Guevara paid a visit to Sri Lanka. The Sirima-Shastri Pact of 1964 and Sirima-Gandhi Pact of 1974 were signed between Sri Lankan and Indian leaders in an attempt to solve the long-standing dispute over the status of plantation workers of Indian origin. In 1974, Kachchatheevu, a small island in Palk Strait, was formally ceded to Sri Lanka. By this time, Sri Lanka was strongly involved in the NAM, and the fifth NAM summit was held in Colombo in 1976. The relationship between Sri Lanka and India became tense under the government of J. R. Jayawardene. To this end, Sri Lanka had briefly adopted a 'Look East' policy, and at one point pursued ASEAN membership over joining SAARC. Further deterioration led to the Indian intervention in the Sri Lankan Civil War and subsequently deployed an Indian Peace Keeping Force in 1987. In the present, Sri Lanka enjoys extensive relations with China, Russia, and Pakistan.

The Sri Lanka Armed Forces, comprising the Sri Lanka Army, the Sri Lanka Navy, and the Sri Lanka Air Force, come under the purview of the Ministry of Defence. The total strength of the three services is about 346,000 personnel, with nearly 36,000 reserves. Sri Lanka has not enforced military conscription. Paramilitary units include the Special Task Force, the Civil Security Force, and the Sri Lanka Coast Guard.

Since independence in 1948, the primary focus of the armed forces has been internal security, crushing three major insurgencies, two by Marxist militants of the JVP and a 26-year-long conflict with the LTTE. The armed forces have been in a continuous mobilised state for the last 30 years. The Sri Lankan Armed Forces have engaged in United Nations peacekeeping operations since the early 1960s, contributing forces to permanent contingents deployed in several UN peacekeeping missions in Chad, Lebanon, and Haiti.

Sri Lanka is the 100th most peaceful country in the world, according to the 2024 Global Peace Index.