Joao Micas, Yosef Nasi was born in Portugal as a Marrano (practicing Judaism in secret), a son of the doctor Agostinho Micas (?-1525), a well known physician and professor at the University of Lisbon. A friend of Maximilian, nephew of the Habsburg King Charles I of Spain.[5] He escaped to Portugal after Charles decided to confiscate the Mendes fortune,[5] and, after the Holy Inquisition began operating against Portuguese Marranos in 1546, moved to Antwerp, in the Habsburg Netherlands, with his aunt, Doña Gracia Mendes Nasi. He studied at the University of Louvain,[5] but had to flee the Inquisition in 1547.[5] He then moved to France and later to Venice, before finally leaving for the Ottoman realm in 1554, where he married Ana (Reyna) Mendes, the daughter of his aunt Gracia Mendes Nasi.[5]