Dynastic union

A dynastic union is a kind of federation with only two different states that are governed by the same dynasty, while their boundaries, their laws and their interests remain distinct. It differs from a personal union in that a personal union is under a monarch, but not under a dynasty, although it depends on the country.

With the assassination of Sancho IV, Navarre was invaded by his cousins Alfonso VI of Castile and Sancho V Ramirez of Aragon, and the latter made king in 1076, leading to more than half-a-century (1076–1134) of Aragonese control.

Marriage of Count of Barcelona Raymond Berengar IV of Barcelona and future Queen of Aragon Petronila of Aragon in 1137 that formed the Crown of Aragon.

Marriage of Isabella I of Castile and Ferdinand II of Aragon on 1469 that laid the foundations for the kingdom of Spain. They didn't ascend to their respective thrones until 1474 and 1479 respectively.

Dynastic union between Spain (the union between the Crowns of Castile and Aragon) and Portugal (1580–1640), generally called the Iberian Union by modern historians, under the Philippine Dynasty.

Marriage of Jogaila and Queen Jadwiga of Poland on 1385, generally called the Union of Krewo. That union laid the foundations for the eventual formation of the Polish–Lithuanian Commonwealth.

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