[1] He was born in Coimbra, Kingdom of Portugal, around 1500, the year of discovery of Brazil by a naval fleet commanded by Pedro Álvares Cabral.
He was fortunate in securing the support of two important Jesuit priests, Fathers Manuel da Nóbrega (1517-1570) and José de Anchieta (1533-1597), who founded São Paulo, on 25 January 1554, which is today one of the largest metropolises in the world.
The Jesuits were stern and persistent missionaries of the Catholic faith with the indigenous people, and their pacification of these warrior societies was one of the most important conquests of Mem de Sá's government.
The Jesuits had conflicts with Duarte da Costa, because he supported the plantation owners, who tried to force slavery upon the Indians.
Mem de Sá opposed the usury of the Portuguese plantation owners in their trade in Indian slaves and helped the Jesuits expand the number of their aldeias.