In 1836 the mission of Oceania was entrusted to the Society of Mary (Marists), and Jean-Baptiste François Pompallier appointed Vicar Apostolic. He arrived at Hokianga on 10 January 1838 with one priest, one brother, a small supply of goods, and almost no money. He established a station at Papakawau and some converts were made, but most of the Maoris round Hokianga were already Methodists and openly hostile. In the following year more priests and catechists arrived bringing money and a printing press. By 1840 the headquarters of the mission had been shifted to Kororareka, and Maoris had been baptised at the Bay of Islands, Hokianga, Kaipara, Whangaroa, and Mangonui.

1840–70

The Catholic mission was officially under the protection of the French Government and was visited by French naval vessels. This caused some hostility towards it from Governors Hobson and FitzRoy, as well as the Protestant missionaries. Pompallier, however, always tried to remain aloof from politics. His method of conversion was to visit as many villages as possible and then to send a more or less itinerant priest into the district and, finally, to erect the buildings of a permanent station. Bishop Pompallier himself made three voyages round the east coasts of the North and South Islands in 1840 and 1841 before setting out on a visit to his island missions. A report to the Sacred Congregation of Propaganda in 1841 showed 164 tribes as Catholic, 1,000 baptised neophytes, and about 45,000 catechumens, but it is clear that most of these Maoris had had only the instruction given by the Bishop or a priest on a brief visit, and later estimates by Marist fathers are very much lower. In nearly all districts Anglican or Wesleyan missionaries were already established, and acrimonious public debates confused further the Maoris' ideas of Christianity.

During 1840 stations had been consecrated at Whangaroa, Tauranga, Kaipara, and Akaroa, where French colonists were expected. As further priests and brothers arrived, stations were established at Rangiaowhia (Waikato), Opotiki, Auckland, and Rotorua. No Marist priests came after 1843, and most of those already in New Zealand accompanied Father Viard when he was appointed Bishop of Wellington in 1851. Although Pompallier recruited priests and nuns in Europe between 1846 and 1849 and subsequently opened schools, lack of money, and finally the Maori Wars, brought work to a halt.

In the Wellington diocese there were estimated to be in 1853 about 1,000 Maori Catholics, principally at Hawke's Bay, Wanganui River, and Otaki, but by 1868 all the former missionaries had been transferred to European parishes.

1870

After the Maori Wars, Father James McDonald was for some years practically the only priest on the Maori mission, but he visited from Hokianga to the Waikato. In the 1880s the Mill Hill fathers were invited to conduct the Maori mission in the Auckland diocese. During the following 50 years, stations were re-established in Northland, Bay of Plenty, Waikato, and the King Country, and St. Peter's College, Northcote, was founded for training Maori catechists. In the Wellington diocese only Sister Mary Joseph Aubert at Hawke's Bay was still respected and listened to by the Maoris. At her suggestion a missioner was appointed to Hawke's Bay in 1879. In 1881 this priest, Father Soulas, visited the Wanganui River and shortly afterwards re-established a station there. The Society of Mary began to send out priests again in 1884, and by 1887 there were again estimated to be about 1,000 Maori Catholics at Hawke's Bay, Otaki, and on the Wanganui River. From these small beginnings the Catholic church was rebuilt, and at the 1961 census had 28,656 adherents out of a total Maori population of 167,086.