The population of Sri Lanka was estimated to be 17.6 million in mid-1993. At the last Census, held in 1981, it was 14,850,001.
The Sinhalese, whose language belongs to the Indo-Aryan family and who first colonised the island from North India in the 6th Century B.C., were, at the Census of 1981, still the largest ethnic group being 74% of the population. They fall into two categories viz. Kandyan Sinhalese and Low Country Sinhalese. The former were 29.1% of the total population according to the Census of 1971.They are not ethnically distinct from each other the distinction being based on the political division of the country as at 1815.
The account of the arrival of the Sinhalese in the 6th Century B.C. under the leadership of a North Indian prince called Vijaya given in the Dipavansa and the Mahavansa (historical chronicles of the Sinhalese) is corroborated by archaeological evidence. Ceramic ware found in the course of excavation in the Anuradhapura citadel area has been dated by radio carbon and photoluminescence methods as belonging to the 6th century B.C. An inscription found on the rim of a vessel is in the Brahmi script and reads " .biya Anuradha." According to the Dipavansa and the Mahavansa Anuradha was the name of one of Vijayas ministers.
The Sinhalese encountered tribes of indigenous people collectively called Yakkhas and assimilated most of them in the course of time. The Yakkhas have been later referred to as Veddas. Immigration from South India in much later times were also assimilated until the desolation of the dry zone combined with the occupation of the north by the Portuguese and the Dutch isolated later immigrants from the Sinhalese.
Buddhism was formally introduced to the island in the 3rd century B.C. by a Buddhist mission sent by the Indian Emperor Asoka under the leadership of his son the Thera Mahinda who thereafter lived his entire life in Sri Lanka. Almost the entire population became Buddhist and thus Buddhism became the national religion without any royal decree. Other religions however were tolerated and their followers were free to profess them publicly and privately. Today 69.3% of the total population are Buddhists; almost all of them are Sinhalese. Hindus, all of them Tamil, are 15.5%, Muslims 7.6%, Roman Catholics 6.8%, while non-Roman Catholic Christians of all denominations are only 0.7% of the population.
The ancient Sinhalese had extended their settlements over the entirety of the dry zone including modern Jaffnapatnam as well as over substantial parts of the wet zone by the first century B.C. as evidenced by their numerous inscriptions. Later they seem to have abandoned the wet zone districts till about the 10th century A.D. Jaffnapatnam itself was entirely Sinhala populated till after mediaeval times as shown by place names still in use there are over one thousand Sinhala place names in the Jaffnapatnam peninsula which are superficially and transparently Tamilised. This is indicative of peaceful rather than hostile colonisation.
Before their decline under imperialist European domination in and after the 16th century, the Sinhalese had some remarkable achievements for a race comparatively small in numbers:
The development of a complex science and technology of large scale irrigation not found anywhere else in the world. "Neither in the lands of their (i.e. of the Indo-Aryan settlers) origin nor in South India did there develop an irrigation system of the magnitude or complexity of that which the Sinhalese afterwards constructed in Ceylon; nothing comparable and contemporaneous (i.e. 1st century A.D 12th century A.D.) with the ancient dam, canal and tank system of Ceylon , mingling the waters of rivers flowing in different directions is known in continental India" (C.W. Nicholas, A Short Account of the History of Irrigation Works, JRASCB 1960 pp.43-69).
"It may be assumed, therefore, that the formation of all reservoirs of a class with embankments much higher than those of simple village tanks was due to the constructive genius of the Sinhalese themselves. At an early date they undertook the raising of great earthen embankments, often some miles in length, across many suitable valleys, thus intercepting the flow of streams, and storing up during the rainy seasons, in the reservoirs thus formed, immense sheets of water for the irrigation of large tracts of land lower down in the valleys " (H. Parker, Ancient Ceylon, pp.349-350).The establishment, over the years, at Anuradhapura (the capital for over a thousand years) of the most important centres of Buddhist learning in the world; Sri Lanka became the home of Theravada Buddhism and the repository of Buddhist literature.
A high degree of development of architecture and civil engineering as demonstrated by the huge dome shaped relic chambers or dagabas " ..the constructive and artistic genius of the Sinhalese race proceeded in the following century (i.e. 2nd century B.C.) to develop the design to an extent not found elsewhere. The most important examples erected in Ceylon are comparable with the greatest pyramids of Egypt .the two largest dagabas at Anuradhapura surpass in contents, and three exceeded in height all but the two enormous pyramids Khufru and Khafra at Gizeh" (Parker, op.cit.p.262).
The creation of a historical literature. "One of the greatest contributions of the Sinhalese people to the cultural development of South and South East Asia and to world literature is the creation of a historic literature. It is well- known that on the Indian sub-continent before the invasion of the Islamic conquerors virtually no historic literature had developed. ...Sri Lanka tells a different story. In the Dipavamsa and Mahavamsa and in various other Sinhalese texts, we are given an account of the political and cultural history of the island from earliest times until the present time" (Heinz Bechert, Wilhelm Geiger His Life and Works, 2nd ed. P.69). Even the identification of Emperor Asoka was made possible by the Mahavansa; so is the dating of the history of South India.
Sinhalese is the oldest living Indo-Aryan language. It is possible to follow the evolution and development of this language from the third century B.C. to the present time by the study of inscriptions and literature.
The dominant constitutional principle from at least the second century B.C. to modern times was that the entire island was subject to a single sovereignty. The Sinhalese lost their independence following a conditional treaty of cession with the British signed on 2nd March 1815. In his Sketches of Ceylon History (1906) Ponnambalam Arunachalam a leading Tamil of his day has written that " .the Sinhalese voluntarily surrendered their Island to the British Sovereign with full reservation of their rights and liberties. They may thus claim to be one of the few ancient races of the world who have not been conquered."