The Spanish monarchy of the 15th century rose from almost six hundred years of intermarrying between four families - the Houses of Castile, Leon, Aragon, and Navarre. The kings of Spain, however, were of little consequence among the crowned heads of Europe until the 13th century. Before that time, they lived in uncomfortably cramped quarters in the north of Spain, shut off from the south by the occupation of the Moors. But with the victory of the Castilian King Alfonso VIII at the Battle of the Navas de Tolosa in 1212 AD, the Spanish monarchs began a slow push to reclaim the peninsula that would continue for the next three hundred years.
In the 15th century, two of the four kingdoms of Spain would rise to supremacy - Castile in the west and Aragon in the east. The marriage of Isabella I of Castile and Ferdinand II of Aragon - who became known as the Catholic Kings - brought nearly all of Spain together under the control of one monarchy. And in 1492, they would change the face of Spain forever, for in that year the Catholics overtook the last Moorish stronghold in Spain, uniting the country for the first time in history. And of course in the same year a certain Christopher Columbus would make an extraordinary discovery, giving the Spanish monarchs the largest and wealthiest empire since the fall of the Caesars.