Genetic evidence suggests that just over 4 millennia ago a group of Indian travellers landed in Australia and stayed.The evidence emerged a few years ago after a group of Aboriginal men’s Y chromosomes matched with Y chromosomes typically found in Indian men.
Numismatic, archaeological and literary sources corroborate that the Sangam period lasted for about six centuries, from 300 BC to AD 300.
The recent excavations in Alagankulam archaeological site suggests that Alagankulam is one of the important trade centre or port city in Sangam Era.
The Pandyan capital Madurai was in the deep south away from the coast.
They had extensive trade links with the south east Asian maritime empires of Srivijaya and their successors, as well as contacts, even formal diplomatic contacts, reaching as far as the Roman Empire.
Three dynasties, namely the Chera, Chola and Pandya, ruled the area of present-day Tamil Nadu and Kerala.
The Chera ruled the whole of present-day Kerala and parts of western Tamil Nadu comprising Coimbatore, Dharmapuri, Karur, Salem and Erode districts from the capital of Vanchi Muthur (thought to be modern day Karur).
According to epigraphist Iravatham Mahadevan, this was the first datable artefact bearing the Indus script to be found in Tamil Nadu.
Mahadevan claimed that the find was evidence of the use of the Harappan language, and therefore that the "Neolithic people of the Tamil country spoke a Tamil language".
The Kalabhras were expelled by the Pallavas, Mutharaiyar, Badami Chalukyas and Pandyas in the 6th century.