In 1517 Augustinian priests (Portuguese) first landed at the port of Chittagong, which was then within the Diocese of Goa, as was practically all of India at that time. (Chittagong is today no longer part of India, but of Bangladesh.) View a map of eastern India and Bangladesh at:http://mapsofindia.com/maps/east/east.htm
Chittagong, city and port in south-eastern Bangladesh, on the Karnaphuli River, near the Bay of Bengal. The Moguls of Bengal were continually trying to wrest Chittagong from the dominion of the Emperor of Arracan. Twice they almost succeeded in taking it by surprise, and from that time onwards this potentate always kept a large body of Portuguese mercenaries (i.e., soldiers for money) in his service at Dianga, near Chittagong.
Native rulers whose states were continually exposed to the raids of their enemies, appealed for protection to many independent Portuguese men then numerous in India, and paid them as mercenaries. These Portuguese mercenaries settled in bandels, generally situated on the bank of a river, and received for their military services lands, a monthly pay, and a share of whatever stolen possessions they could carry away after their attacks.
Their numbers increased rapidly, for they married native women, and many native converts came to them for protection and security. Instead of waiting for the attacks of the Moguls, these Portuguese mercenaries (bandels) found it easier and more effective to carry the war into the territory of the enemy, In the employ of the Moguls of Bengal, the Portuguese mercenaries began to make periodic raids on the Benghali coast, carrying away whole populations of Hindu and Mohammedan villages. Thus between 1621 and 1634 they brought back with them to Chittagong 42,000 slaves. For the Augustinians, this was very much a case of "the Faith following the flag" - or the sword. Of these 42,000 slaves, the Augustinians baptized 28,000. They converted besides five thousand natives of the country, called Moguls or Marmas (Moghs). After 1640 the Augustinians were also in Balasore, Ossumpoor, and Rangamati.
In 1612, Portuguese Augustinian missionaries introduced the Christian Faith in Dhaka. In 1628, they established a church, called the 'Church of the Assumption', in Narinda area of the city. The second church of Dhaka was built in 1677 at Tejgaon. In 1695, the church of Saint Nicholas of Tolentino was constructed at Nagori, 25 kilometres northeast of Dhaka. In 1682 there were 14,120 Roman Catholics in the Bangladesh territory.
As the Bangladeshi Muslims have Arabic and Persian surnames, so do the Catholics converted by the Portuguese have Portuguese surnames, such as Gomes, Rozario, D'Rozario, Cruze, D'Cruze, Dores, D'Silva, D'Souza, Costa, D'Costa, Palma, Pinheiro, Pereira Rego, Ribeiro, Rodrigues, Serrao, Gonsalves, and Corraya. To recognize Catholic converts by names, the missionaries used to give one Christian name and one of their surnames to each candidate for the Christian Faith. The later Catholic missionaries from France, the United States, Canada, and Italy did not follow the Portuguese in naming the new Christians.