It is during this period just before the advent of the Christian era that Jaffna became a link in the South Asian and transoceanic maritime trade Two factors contributed to this development:
I. It was a common practice to use coastal passages in sea trade routes and the Roman and Indian ships went through the Gulf of Mannar in the Palk Strait crossing Mantai and Pampan to go from the westernt of India to its eastern coast.
II. The Gulf of Mannar-Palk Strait route was also famous for its and conch shell diving.
Emissaries of Sri Lanka went to Rome in the reign of Emperor Claudis (40-54 A.D.). According to Pliny, a freedman of Annius Placamus, while sailing round Arabia, was caught by a storm and landed in Ceylon at the port of Hippuros. He was taken to the king with whom stayed for six months. The king thereafter sent an embassy to Rome. The name of the ambassador-in- chief appears to be Rachias (perhaps Rasiah) and, in the view of J.E.Tennent, he was a representative of the Raja of Jaffna.
It was during this phase that Buddhism became “an integral part the heritage of Jaffna”. There are many places in the Jaffna Peninsula whose names are connected with Buddhist viharas. The Buddhist remains at Kantarodai, perhaps burial monuments of monks, are found in a group at a specific area with this distinctive feature: the architectural use of coral and limestone. It is interesting to note that the “limestone and coral architectural tradition of Jaffna in fact started with the Buddhist monuments and flourished for nearly two millennia till the advent of concrete”.
According to some, the ambassadors of Buddhism sent by Emperor Asoka landed in the Peninsula.
Buddhism, together with Prakrti, the language of Buddhism that helped to form a homogeneous population in the rest of Sri Lanka, failed to establish a permanent foothold in Jaffna. To be sure, it was able to cohabit or syncretise with the folk – religion (Hinduism) of Jaffna. However, perhaps at the end of the first millennium AD, many settlements with their Buddhist structures were abandoned.