Ursula Germaine of Foix was an early modern French noblewoman from the House of Foix. By marriage to King Ferdinand II of Aragon, she was Queen of Aragon, Majorca, Naples, Sardinia, Sicily, and Valencia and Princess of Catalonia from 1506 to 1516 and Queen of Navarre from 1512 to 1516. She was Vicereine of Valencia from 1523 until her death in 1536, jointly with her second and third husbands, respectively Johann of Brandenburg-Ansbach and Ferdinand, Duke of Calabria. By her third marriage, she was Duchess of Calabria.

Ferdinand II was King of Aragon from 1479 until his death in 1516. As the husband of Queen Isabella I of Castile, he was also King of Castile from 1475 to 1504. He reigned jointly with Isabella over a dynastically unified Spain; together they are known as the Catholic Monarchs. Ferdinand is considered the de facto first king of Spain, and was described as such during his reign, even though, legally, Castile and Aragon remained two separate kingdoms until they were formally united by the Nueva Planta decrees issued between 1707 and 1716.