Isabella and Ferdinand By biancapadova Apr 22, 1451 Birth of Isabella Oct 18, 1469 Marrige of Isabella and Ferdinand Therefore combining their kingdoms Dec 11, 1474 Began to Rule Castile And began to unite the kingdom under Christianity Jan 15, 1475 Aragon, Sicily, Naples, Valencia, Sardenia, and Navarre fall under the rule of Isabella This is because Ferdinand becomes ruler and seeing how they are married they are also under the rule of Isabella. Jul 12, 1492 Conquered Muslims Aug 3, 1492 Sent out Christopher Colombus Nov 26, 1504 Death of Isabella