Isabella I was the Queen of Castile and after her husband Ferdinand II became the King of Aragon, Isabella became the Queen consort of Aragon. Marriage of the royal couple laid foundation for political unification of Spain and although Castile and Aragon remained de jure two different kingdoms till Philip V of Spain signed the Nueva Planta Decrees of 1716, Isabella and Ferdinand are respectively considered the first de facto Queen and King of Spain. Isabella reorganized the governmental system in Castile, unburdened the huge debt left by her predecessor, and substantially decreased crime rate of the kingdom. The royal couple gained repute for finishing the Reconquista, emerging victorious in the Granada War against Nasrid dynasty's Emirate of Granada leading to end of all Islamic rules on the Iberian peninsula and annexation of Granada by Castile. This victory of the Christians led Pope Alexander VI to award the couple the title of Catholic Monarchs. The Catholic Church later recognized her as a Servant of God. The royal couple also sponsored first voyage of Christopher Columbus in 1492 when the latter independently discovered the Americas and magnetic declination.