The Sinhalese make up 74.9% of the population and are concentrated in the densely populated south-west and central parts of the island. The Sri Lanka Tamils, who live predominantly in the north and east of the island, form the largest minority group at 11.1% of the population.
The Moors, descendants of Arab traders that settled in Sri Lanka and married local women, form the third largest ethnic group at 9.3% of the population. They are mostly concentrated in urban areas in the southern parts of the island with substantial populations in the Central and Eastern provinces. During times of Portuguese colonisation, Moors were persecuted, and many forced to retreat to the central highlands and the eastern coast.
There are also Indian Tamils who form a distinct ethnic group comprising 4.1% of the population. The British brought them to Sri Lanka in the 19th century as tea and rubber plantation workers, and they remain concentrated in the "tea country" of south-central Sri Lanka. The Indian Tamils of Sri Lanka were considered to be "stateless" and over 300 000 Indian Tamils were deported back to India, due to the agreement between Sri Lanka and India in 1964. Under the pact, India granted citizenship to the remainder, some 200,000 of whom now live in India. Another 75,000 Indian Tamils, who themselves or whose parents once applied for Indian citizenship, now wish to remain in Sri Lanka. The government has stated these Tamils will not be forced to return to India, although they are not technically citizens of Sri Lanka. By the 1990s most Indian Tamils had received Sri Lankan citizenship, and some even were not granted Sri Lankan citizenship until 2003.
Smaller minorities include the Malays who descent from South East Asian settlers, and the Burghers, who are descendants of European colonists, principally from Portugal, the Netherlands and the UK. (Wikipedia)