Think of Egyptians, Romans, Greeks, Khmer, Champa and Eastern Indian dynasties. What connects them? Not just the fact that they were colossal empires, but ones that specialised in maritime trade. The secrets to unlocking the history behind any region is often linked to its description in ancient literature and based on accounts of sea faring traders and merchants.
Tamil Nadu has numerous entries for ports of commercial trade dating back centuries ago mentioned frequently in Sangam literature as well as that famous book for seafarers, Periplus of Erythrean Sea. Mylapore, Mamalla/Poonjeri, Kaveripumpattinam, Nagapattinam, Korkai and Kumari were important maritime trade centres.