Isabella I was born in 1451. From 1474 to 1504, she was Queen of Castile, presiding over a dynastically united Spain with her husband, King Ferdinand II of Aragon. After Ferdinand II rose to the throne of Aragon in 1479, Isabella I became Queen of Aragon. Isabella and Ferdinand are known as the Catholic Monarchs while they are together. Here's a quiz based on Isabella I. Let's play the quiz.