What is Personal union?
A '''personal union''' is a relationship of two or more sovereign [[state]]s, which, through law, share the same person as their [[head of state]]. Personal unions can begin for very different reasons. In many cases a princess who is already married to a king becomes pregnant, and their child inherits [[monarchy|the crown]] of both countries. However, a personal union sometimes was seen as a means against uprisings if a state wants an annexation of an other state. The unions can be written down in a constitution, which clearly expresses that both states shall share the same person as head of state. When that is not the case, a personal union can easily be broken. == Some examples == === Andorra === * ''Partial'' personal union with [[France]] since [[1607]] (the French president, and formerly the king of France, is one of the Heads of State in Andorra, the other co-head of state is the [[Bishop]] of La Seu d'Urgell, [[Catalonia]], [[Spain]].) === Belgium === Personal union with the Congo Free State from 1885 to 1908, when it annexed the Congo Free State. === Bohemia === * Personal union with Poland 1003 - 1004 (Bohemia occupied by Poles) * Personal union with Poland 1300 - 1306 and Hungary 1301 - 1305 (Wenceslas II and Wenceslas III) * Personal union with Luxembourg 1313 - 1378 and 1383 - 1388 * Personal union with Hungary 1419-1439 (Sigismund of Luxemburg and his son in law) and 1490 - 1526 (Jagellon dynasty) * Personal union with Austria and Hungary 1526 - 1918 (except years 1619 - 1620) === Brandenburg === * Personal union with the [[Duchy of Prussia]] from 1618, when [[Albert Frederick, Duke of Prussia]] died without male heirs and his son in law [[John Sigismund, Elector of Brandenburg]] became ruler of both countries. Brandenburg and Prussia maintained separate governments and seats of power in [[Berlin]] and [[Königsberg]] respectively until 1701, when [[Frederick William I of Prussia|Frederick William I]] consolidated them into one government. === Congo Free State === Personal union with Bel