Paravars were the first whole community in India to convert to Christianity in the mid 16th century.

The mass conversion of Paravars to Christianity took place during the period 1535-1538. The motive for this mass conversion was not entirely spiritual or religious, but a necessity for their survival at that period. Paravars were a privileged community of fisherman spread over the entire coast line of southern peninsula, specialised in pearl fishery. When the Arab fishermen came and took over the pearl fishery at the instance of local Hindu rulers, this community was exposed to the oppression of Muslim fishermen and Hindu rulers. To escape from the persecution Paravars could not find any solution except seeking the protection of the Portuguese. They sought the help of a local Malabari Christian covert named Joao da Cruz, who advised them to become Christians and seek the help of Portuguese, who would afford them naval support at sea and adequate protection to continue their trade.

Paravars found no other way except to accept his advise for their survival. Joao da Cruz did the liaison with the Portuguese and got their consent for the proposal. First twenty of their community leaders known as "Pattangattiyars" (பட்டங்கட்டியர்) were taken by Joao da Cruz to Cochin and got them baptized. In response the Portuguese sent their Naval squadron to Cape Comerin and released the Paravars from Muslim captivity. Interestingly the "Pattangattiyars" who were thus baptized took on the family name "da Cruz" because of Joao da Cruz, who helped them at the time of need. Since then it was a custom for the leaders of the community to be called as "da Cruz".

The Paravars apart from getting converted also had to pay 60,000 fanams to Portuguese as protection money. This was further used to induce more conversions. Miguel Vaz the Portuguese Vicar General visited the Paravars accompanied by four priests and administered baptism to about twenty thousand people. In a few years, the number rose to eighty thousand men, women, and children and the Christianity spread among these people,who were settled on the Malabar and Coramandel coast. The Paravars had the protection of the Portuguese fleet to follow their profession undisturbed.

It is admitted on all ccounts, that one of the greatest and most successful group conversion movements in India was that of the Paravars in the 16th century.