Juan Masías was orphaned at four in a small Extremaduran village in Spain. He worked as a shepherd boy until eighteen, when he made the long journey to Seville and then on to Cartagena in the Americas (1619), eventually reaching Lima around 1622 at thirty-seven. There he entered the Dominican convent of Santa María Magdalena (the recoletos house of San Pedro) as a lay brother in 1622, in the same generation as Martin de Porres at the larger Santo Rosario convent across the city.
He served as porter and almoner of the convent for the next twenty-three years — distributing food and clothing daily at the convent gate to the poor of the city (Spaniards, criollos, mestizos, mulattos, Africans, indigenous Andeans — all on equal footing), praying the Rosary continuously (his rosary, broken multiple times by daily use, was preserved as a relic), and supporting in particular the destitute Spanish immigrants and dispossessed indigenous communities of Lima.
He was close friends with Rose of Lima (until her death in 1617) and especially with Martin de Porres of the Santo Rosario convent across the city — the two Dominican lay brothers, alike in spirituality and in their refusal of social caste, regularly visited each other and prayed together. Juan died at the convent on September 16, 1645. Canonized 1975.