[12][13] During Maputeoa's reign, the country, which was deeply rooted in native beliefs and even cannibalism, became a Roman Catholic community.

This was accomplished by removing all vestiges of native beliefs, such as destroying the traditional wooden images of their indigenous faith deified in maraes and replacing them with churches.

[14] He learned about Christianity from the island's missionaries, headed by the French Picpus priests, Honoré Laval and François Caret.

[20] Mangareva also had nominal control over the other Gambier Islands including Akamaru, Aukena, and Taravai, which had their own kings who were vassals to the monarch at Rikitea.

He took the name Gregorio after baptism in honor of Pope Gregory XVI who had deputed the missionaries to eastern Oceania, and solemnly placed his islands under the protection of the Blessed Virgin Mary.

"[25][26][27] He was succeeded as King of Mangareva by his young son, Joseph Gregorio II, with his widow Queen Maria Eutokia Toaputeitou as regent.