Throughout the sixteenth century, the majority of the Christian territories of Europe went through a political evolution towards authoritarian monarchies. At this time, the Iberian Peninsula became the nucleus of a political entity sui generis, characterized by the consolidation of numerous kingdoms and territories under the power of one prince. This, along with the development of strong royal power, transformed it into one of the pre-eminent models of authoritarian monarchy, or the “Modern State.”

The Catholic Monarchs carried out the first great process of territorial aggregation, which constituted the nucleus of the Hispanic monarchy, with the Crown of Castile playing a prominent role. The royal wedding in 1469 set the basis for the two great Spanish Crowns, or groups of kingdoms, to be ruled under a single king who would also receive the rest of the conquered territories: Granada, Naples and Navarra, as well as the Canary Islands and the vast American land. This first process of integration would be followed by two more similar processes under the reigns of Charles V and Philip II, respectively. The Spanish monarchy became a formidable territorial assembly as a result of the partially fortuitous confluence of four dynastic lines under Charles V: Castile with the Americas, Aragon, Bourgogne and the Low Countries, and the Hapsburgs with the Holy Empire. The last large territorial annexation occurred in 1580 when Philip II, heir of the Hapsburg dominions and of the imperial title, incorporated Portugal and its colonies overseas.