He was born Juan de Yepes y Álvarez at Fontiveros, Old Castile into a converso family (descendants of Jewish converts to Catholicism) in Fontiveros, near Ávila, a town of around 2,000 people. His father, Gonzalo, was an accountant to richer relatives who were silk merchants. In 1529 Gonzalo married John's mother, Catalina, who was an orphan of a lower class; he was rejected by his family and forced to work with his wife as a weaver. John's father died in 1545, while John was still only around three years old. Two years later, John's older brother, Luis, died, probably as a result of malnourishment due to the poverty to which the family had been reduced. As a result, John's mother Catalina took John and his surviving brother Francisco, first to Arévalo, in 1548 and then in 1551 to Medina del Campo, where she was able to find work.