The Southern Province of Sri Lanka was a small geographic area consisting of the regions of Galle, Matara and Hambantota. This province in 1861 had the area of 2,147 square miles and a total population of 325,000. The region was economically backward. The mission of Galle comprised of almost whole Southern province of then Ceylon. The Vicariate Apostolic of the South or of Colombo comprised of the Southern, Western, and Central Provinces in 1861.

The mission of Galle began from the 36 mile from Colombo stretched southwards for 72 miles along the coast to the Southeast of the island. The town of Galle was 72 miles from Colombo and was the port of call for all the steamers that ply on the Indian Ocean. Galle town was at fifty miles from Dondra on the coast towards the west. Dondra Head town is the most southern point of the island. The interior of this region was completely and exclusively inhabited by Buddhists, Sinhalese speaking. There were also some institutions of Protestants.

In the town of Galle there were few Catholics mostly descend from the Europeans, but were poor. On the road towards Colombo there were Catholics of three or four families. Thus, the Catholics were very few. In 1854 there were 1500 in the whole district, and there were also less than 100 English garrison.

The mission of Galle was the least numerous and the least important for quality and number of Christians, who, just because worse, they could not even maintain a missionary. Therefore Galle for some years had not been assigned a missionary both for the reasons mentioned and much more because there were not enough missionaries for other places which were by far more important. This mission was visited only occasionally.

Mgr. Eugene de Mazenod at the request of Propaganda Fide sent four Oblates to the Vicariate Apostolic of the South in 1851. It was the first group of Oblates to be sent to the Southern (Colombo) Vicariate. They were placed under the jurisdiction of Bishop Giuseppe Maria Bravi, a Sylvestrine, Vicar Apostolic of Colombo, whereas the Oblates who were already working since 1847 in the North were under the jurisdiction of Bishop Orazio Bettachini, an Oratorian, Vicar Apostolic of Jaffna. But both groups had Fr. Étienne Semeria, o.m.i., as their religious superior.

The first oblate to go there was Fr. Jean-Pierre Perréard, o.m.i., transferred on 31 August 1853. He was looking after the areas of Galle, Matara and Hambantota. But in 1854 he was removed from the mission.

Since the port of Galle was the port of call for all the steamers on Indian Ocean, all most all the missionaries entered into the country through Galle.

According to the report of Bishop Bravi, on 6 September 1858, on his Pastoral Visitation there were two churches: one in Galle close to the fort and on top of a hill with a commanding view of the sea; and the other at Matara, at 35 miles distance from Galle going towards the east, close to the most southern point of the island of Sri Lanka.

At the beginning of 1866, the General Administration of the Oblates decided to pull out the Oblates serving in the Vicariate of Colombo and sent them to join the Oblates in the Vicariate of Jaffna. Thus, all the three Oblates left the vicariate. Again it was in 1883 when Propaganda Fide entrusted the vicariate of Colombo to Oblates and transferred Bishop Ernest Christophe Bonjean o.m.i., from Jaffna to the vicariate, Oblates came again and extended their services in most parts of the vicariate.

Jerome Velichor, o.m.i.