An ancient Bengali princess travelling through India was kidnapped by a lion, by whom she had a son and daughter. On reaching manhood, the boy slew his fond father, married his sister and established a kingdom in western India. Their son, prince Vijaya, proved unmanageable and was banished along with his supporters.
Setting sail into the unknown they landed in Sri Lanka in the year of Buddha's death (486 BC). Vijaya married then abandoned one of the demons who inhabited the island, subsequently marrying a south Indian princess who brought to Sri Lanka a thousand craftsmen and their families. So runs the ancient story.
Despite its legendary character, the story contains elements that are supported by archaeology. Unlike the mainland, Sri Lanka seems never to have been colonized by early farmers, its indigenous population continuing to live by hunting, fishing and gathering well into the 1st millennium BC, when the appearance of megalithic monuments, pottery and iron tools shows that Sri Lanka and south India were in contact.
The island was still sparsely populated and remained so until the development of irrigation works made possible a great rise in population in the Dry Zone. Although it is impossible to demonstrate the arrival of individual groups, the expansion of Indo-Aryan speakers throughout northern India during the 1st millennium BC and the trade links that existed between different areas of the subcontinent make an expedition like Vijaya's quite feasible.
Certainly the earliest written records in Sri Lanka are in an Indo-Aryan language, indicating that by historical times literate Sri Lankans, and possibly the bulk of the population, were Indo-Aryan speakers.
Recent excavations at Anuradhapura have put flesh on the ancient stories, showing the establishment of a small settlement here around the 6th century BC and its massive expansion in subsequent years.