 Both his father (also named Juan de Lugo) and his mother (Teresa de Quiroga, whose family name he bore for a time as was custom for the second son) were of noble birth.At the age of three years he could read printed or written books; at ten, he received the tonsure; at fourteen he defended a public thesis in logic and at about the same time was appointed by King Philip II of Spain to an ecclesiastical benefice which he retained until he became a priest in 1618.Like his elder brother, Francis, he was sent by his father to the University of Salamanca to study law.