Isabel of Portugal was born on 24 October 1503. As the daughter of King Manuel of Portugal, she received a brilliant Humanist education in languages and mathematics. Being an intelligent, refined, and beautiful princess from Europe’s wealthiest kingdom made her the most desirable marriage candidate in the eyes of Catholic sovereigns. Nothing less than Emperor Charles V had been considered worthy of her.
Through their mothers — the daughters of the Catholic Monarchs Isabella of Castile and Ferdinand of Aragon — the newlyweds were first cousins. Isabel was not the first Empress of Portuguese origin: Charles’s great-grandmother Eleanor, the wife of Emperor Frederick III, had been Isabel’s paternal great-aunt. The couple also shared English ancestry, both descending from Edward III of England through his granddaughter Philippa of Lancaster.
Isabel’s education, upbringing, and character had prepared her exceptionally well for the role and governmental duties of an Empress. Despite her capable regency of Spain during Charles’s frequent absences, she has largely remained a shadowed figure in his biographies.