Sinhalese kings used to marry into Tamil royal families. The royal brides and their retinues were absorbed into Sinhalese culture. Colonies of merchants did not plant themselves permanently at one place and therefore did not leave an impact on the country. Small groups of craftsmen settled in Sinhalese villages in a predominantly Sinhalese population and were assimilated. There is evidence that some Sinhalese castes originated in this manner. An ever-increasing number of mercenary soldiers were brought from south India by the Sinhalese kings. These people lived in their own cantonments with little or no contact with the Sinhalese. Here they continued practising their own ways of life, language, and religion. Yet, from the seventh century onward, they were a powerful force in the country, interfering in the dynastic struggles of the Sinhalese and helping to put in power kings favorable to their own interests. Their leaders were appointed to high offices in the state. The first temporary shift of the capital from Anuradhapura was caused by the desire of the ruling monarch to rid himself of Tamil political influence. From this time, accentuated by growing contact between the Sinhalese and the Tamil kingdoms of south India, Tamil influence on Sinhalese governmental organization was greater than ever. This was particularly so in the sphere of land tenure and taxation, where terms of south Indian origin now made their appearance and were increasingly in vogue thereafter. Titles of officers that are of Tamil origin were also in evidence. Some of these terms are still in existence.

Hindu temples belonging to this early period which are scattered in many parts of the country attest to the presence of Tamil settler communities. There are three Siva temples of great antiquity, and these enable us to make reasonable inferences regarding Tamil settlements in the early centuries of the Christian era. Thirukethisvaram at Mantota and Konesvaram at Trincomalee are mentioned in early Tamil literature as famous Saiva centers which attracted pilgrims from south India. Thirukovil, a few miles south of Batticaloa, seems also to be a temple of the early period. These three places may thus be taken to be the seats of the oldest Tamil colonies of people engaged in trade, agriculture, and fishing. The coastal areas of the Jaffna peninsula, too, seem to have been colonized, particularly the ports at which small boats could call. There is indication of a sixth-century movement from Jaffna along the coast to Batticaloa. By the tenth century, the first stage of Tamil settlements was complete. Research on the laws of the Ceylon Tamil peoples seems to indicate that most of the settlers of this early stage came from the Malabar coast. This is understandable, as trading and migrating movements were in evidence from very early times among the peoples of this coast. They seem to have handed down to succeeding