The Tamil people are native to the state of Tamil Nadu in South India and their traditional homeland, according to Sangam period sources extended from Vengadam to Kanyakumari. It also included the present-day Kerala. However, between the 2nd century BC and the 14th century AD, Tamil trader colonies were established in many parts of West Asia, South-East Asia and Egypt apart from the islands of the Indian Ocean. The first large-scale migrations of Tamils was to Sri Lanka, which lay closest to the Indian mainland, and they formed a majority in the northern and north-east parts of the island by the time of the Medieval Cholas (870-1279 CE).
During British rule, large numbers of Tamils from the Madras Presidency were transported to Malaya, Singapore, Mauritius, Seychelles, South Africa, Central Sri Lanka, Reunion, Trinidad and Tobago, Fiji and Guyana to work as indentured labourers in sugar plantations. There was also a large mercantile class in Burma, Sri Lanka, South-East Asia and the Persian Gulf countries.
Sri Lanka 
The first colonies of Tamil-speaking people outside the Indian mainland were founded in Sri Lanka. While there has been evidence of pre-historic Tamil settlements in Sri Lanka, the earliest records of a Tamil presence in the island date from about 185 BC, when the legendary Chola king Elara invaded and conquered Sri Lanka. Migration accelerated between the 5th and 14th centuries AD, when the Pallava, Chola and Pandya kings mounted large-scale expeditions to conquer the island. The presence of a large number of Tamil mercenaries in the island by the 11th century CE is indicated by the Velakkara Revolt. The migrations rapidly decreased after the conquest of the Pandya kingdom by the Muslim general Malik Kafur in about 1317 though cultural and commercial contact between the southern Tamil Nadu and northern Sri Lanka continued. The Nayaks of Kandy had matrimonial alliances with the Thanjavur Nayak kingdom. Following the conquest of the Kandy kingdom by the East India Company in 1795, the British ruled the island as a part of Madras Presidency till 1803, when a separate administration was set up. Starting from the middle of the 19th century, the British transported large numbers of Tamils to work as indetured labourers in the hills of central Sri Lanka.
As of 2012, ethnic Tamils constituted 11.2 percent of the total population of Sri Lankan population with large concentrations in the northern, north-eastern and central parts of the island. There has been uninhibited exchange of vocabulary between Tamil and Sinhala. Tamil is one of the official languages of Sri Lanka and is widely read and understood by Sinhalese people.
See also 
- "Dharna against ‘Tamilisation’of KGF - Deccan Herald". cscsarchive.org. "Tamilisation of bangalore"
- "Tamilisation". Lankanewspapers. "Tamilisation of southern sri lanka"
- "Sri Lanka: Sinhalisation of the North and Tamilisation of the South : paths2people". Paths2People. "Tamilisation of southern sri lanka"