The indigenous population of the erstwhile Portuguese colony of Goa underwent a large-scale conversion from Hinduism to Christianity after its conquest and occupation by the Portuguese Empire, led by admiral Afonso de Albuquerque in 1510. After conversion to Roman Catholicism, they were granted Portuguese citizenship. Almost all the present-day Goan Catholics are descendants of these local converts to the religion. They constitute the largest Christian community in Goa and account for 25 per cent of the total Catholic population in India. The Mangalorean Catholic and Karwari Catholic communities of the Indian state of Karnataka are also largely descended from these Goan converts.
During the mid-16th century, the Portuguese colony of Goa, especially the city of Goa, was the center of Christianization in the East. Christianization in Goa was largely limited to the four concelhos (districts) of Bardez, Mormugao, Salcette, and Tiswadi. Furthermore, evangelisation activities were divided in 1555 by the Portuguese viceroy of Goa, Pedro Mascarenhas. He allotted Bardez to the Franciscans, Tiswadi to the Dominicans, and Salcette, together with fifteen southeastern villages of Tiswadi, including Chorão and Divar, to the Jesuits. The city of Velha Goa was shared among all, since all the religious orders had their headquarters there. Prior to that, the Franciscans alone Christianized Goa till 1542. Other less active orders that maintained a presence in Goa were the Augustines, Carmelites, and Theatines. The first mass conversions took place among the Brahmins of Divar, and the Kshatriyas of Carambolim. In Bardez, Mangappa Shenoy of Pilerne was the first Hindu to convert to Christianity in 1555, adopting the name Pero Ribeiro and thus becoming the first Christian of Bardez. His conversion was followed by that of his brother Panduranga and his uncle Balkrishna Shenoy, who is the direct patrilineal ancestor of Goan historian José Gerson da Cunha. In Salcette, Raia was the first village to have been Christianised, when its populace was converted en masse to Christianity in 1560.