During his pontificate (1831–1846), Pope Gregory XVI (1765–1846) founded the Apostolic Vicariate of Melanesia and Micronesia on 19 July 1844 and entrusted it first to the Marists (1845-1850) and then to the Milan missionaries (PIME) from 1850 to 1855.
However, the highly motivated but inexperienced Italian missionaries did not find the conditions conducive for survival and left Melanesia in 1855 — as had, for similar reasons, their predecessors.
The last surviving Italian missionary, Fr Giovanni Mazzucconi (1826–1855, beatified on 19 February 1984), was the victim of a raid by Woodlark Islanders at Milne Bay in 1855.
All pre-colonial Catholic attempts to evangelise the indigenous population and establish permanent missionary activity had failed in New Guinea and the Solomon Islands.
When the project failed in 1881 Lannuzel remained on Matupit Island and could with contact To Litur, a Tolai chief from Beridni on East New Britain.
The Wesleyan Methodists (WMM) arrived in 1875 in the Bismarck Archipelago and started their missionary work on the Gazelle Peninsula on New Britian Island in 1875.
After first contacts with the inhabitants of the area around Port Breton and some attempts to give catechesis to local people, the ship turned off for New Britain.
[12] In 1995, Pope John Paul II beatified Peter To Rot, a catechist and New Guinea native from New Britain blessed for his martyrdom when in 1945 he refused to embrace polygamy and was killed by occupying Japanese forces.
[18] Bishop Alain de Boismenu, Vicar Apostolic of Papua from 1908 to 1945, established missionary and charitable activities based on the mission at Yule Island.
[20] The French mystic and visionary Marie-Thérèse Augustine Noblet (fr), whom de Boismenu exorcised in France in 1921, accompanied him to Papua and assisted at the mission until her death in 1930.
Her story made a profound spiritual impression on the Australian poet James McAuley, who visited Yule Island in 1949 and converted to Catholicism.
[21] Fr William Ross accompanied early expeditions of the Leahy brothers to the Highlands and established a mission at Mount Hagen in 1934.
[25] In 1967 the Australian ophthalmologist, Fr Frank Flynn, was appointed as Administrator of the Cathedral and Director of Catholic Health Services in Papua New Guinea.
[29] Catholics prominent in Papua New Guinea politics include Michael Somare, John Momis (who was a priest for many years) and Bernard Narokobi.