A dynastic union is a type of union with only two different states that are governed under the same dynasty, with their boundaries, their laws, and their interests remaining distinct from each other. Historical examples Union of Kingdom of Aragon and Kingdom of Navarre 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 was made king in 1076, which led to more than half a century (1076–1134) of Aragonese control. Union of Kingdom of Aragon and County of Barcelona 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. Spain (Union of Castile and Aragon) Marriage of Isabella I of Castile and Ferdinand II of Aragon in 1469 that laid the foundations for the kingdom of Spain. They did not ascend to their respective thrones until 1474 and 1479 respectively. Iberian Union (Union of Spain and Portugal) 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. Union of Grand Duchy of Lithuania and Kingdom of Poland 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. Union of Kingdom of France and Kingdom of Navarre Following Salic law, Henry III, King of Navarre, a member of the House of Bourbon, succeeded to the French throne in 1589 upon the extinction of the male line of the House of Valois. Both houses were cadet branches of the Capetian dynasty, the ruling house of the kingdom of France since 987. Union of Kingdom of Scotland and Kingdom of France Norman or French culture first gained a foothold in Scotland during the Davidian Revolution, when King David I introduced Continental-style reforms throughout all aspects of Scottish life: social, religious, economic and administrative. He also invited immigrant French and Anglo-French peoples to Scotland. This effectively created a Franco-Scottish aristocracy, with ties to the French aristocracy as well as many to the Franco-English aristocracy. From the Wars of Scottish Independence, as common enemies of England and its ruling House of Plantagenet, Scotland and France started to enjoy a close diplomatic relationship, the Auld Alliance, from