|Roman Trade routes to the East - India was the number one destination|
Roman traders settled along the sub-continent's east coast and southern Tamil states at places such as Barbaricum (now Karachi), Barygaza, Muziris, Korkai, and Arikamedu - the latter three all being Tamil. Pliny writes in 78AD that the Tamil economy was built almost entirely on international trade, where Tamil or Sri Lankan ships from Southeast Asia and China met Roman shippers arriving from Egypt. Commodities traded included frankincense, ceramics, gold and silver, coral, linen clothing, glass and wine coming from Europe. The Roman ships returned west loaded with silk yarn, cotton cloth, rice, wheat, sesame oil, spices and Chinese made steel (goes to show nothing much has changed). Pliny conservatively estimated Rome's annual trade deficit with Asia was some 100-million sesterces ($2.5-billion). And this was no small deal. Two thousand years later India is still littered with the millions of coins shipped into the country during the reign of the Roman Emperors.
It is also likely India had the world's largest population of Roman expats at the time. The Apostle Thomas (the doubting one) travelled to the sub-continent in 52AD to convert a large Jewish population already established in the north and in the Tamil States. It has been suggested he even converted one of the northern kings, Gundaphorus, and established seven and a half churches in the south (yes, I know, I can't explain the half either), some of which continue as places of worship to this day.