ABSTRACT This text discusses the European system in the modern age, describing the concept of ‘state’ as an object bounded by property rights and its owner’s jurisdiction. In order to maintain the state, it was necessary to keep the inhabitants in a state of submission, through either persuasion or force. State policy consisted in preserving the possessions of the state, improving and increasing it, combining statecraft with the subjects and concert with other state-holders. States were not autonomous units, but domains, and state affairs concerned ways of increasing or maintaining their ownership. When two princes married, they united their states and created a new political and institutional framework, with each spouse taking on the conflicts and alliances of his or her partner, creating entirely new situations. Each peace treaty or alliance was solidly sealed with a dynastic union, as can be seen in the example of the rise of the House of Habsburg, which became the first European power after integrating the inheritances of three great lineages: the Austrian Habsburgs, who contributed fiefdoms and states in Central and Eastern Europe, the House of Burgundy, who contributed states in France and the Low Countries, and the House of Trastámara, who contributed the kingdoms of Castile and Aragon.