[1] In 1548, Francis Xavier visited Mannar and came to Jaffna to persuade the king to cease his persecutions against the Christians.

The whole peninsula having surrendered in 1591 to André Furtado de Mendonça, almost the entire population embraced Christianity.

When the fort of Jaffna capitulated to the Dutch in 1658 there were in the peninsula 50 priests, 1 Jesuit college, 1 Franciscan and 1 Dominican convent, and 14 churches.

For safety the famous miraculous Statue of Our Lady of Miracles, Jaffna patao ( புதுமை மாதா / Puthumai Matha 1614-1658) was smuggled out of the island by Portuguese prisoners.

Since 1658, the statue has been kept in the church of Sao Pedro situated along the Mandovi river in Bainguinim, Goa, India.

To this diocese belongs the Island of Mannar rendered famous by the apostolic labours of Francis Xavier and by the martyrdom of 600 to 700 Christians, executed by order of the King of Jaffna.

In 1845, Ceylon was divided into the two vicariates of Colombo and Jaffna, with Bishop Orazio Bettachini as vicar Apostolic of the latter.

It is especially devoted to higher English education, and prepares its students for the Cambridge Junior and Senior examinations and for the London University Intermediate.

Some years ago it was thought expedient to come into closer contact with non-Catholics and especially with the higher classes of Hindus.

Jaffna convent, conducted by the Sisters of the Holy Family of Bordeaux, follows the same junior and senior courses, for the education of girls, as St. Patrick's.

The diocese has conferences of St. Vincent de Paul and young men's associations for the working classes.