Personal union


A personal union is a combination of two or more monarchical states that have the same monarch while their boundaries, laws, and interests remain distinct. A real union, by contrast, involves the constituent states being to some extent interlinked, such as by sharing some limited governmental institutions. It differs from a federation in that each constituent state has an independent government, whereas a federal state is united by a central government. The ruler in a personal union does not need to be a hereditary monarch.
The term was coined by German jurist Johann Stephan Pütter, introducing it into Elementa iuris publici germanici of 1760.
Personal unions can arise for several reasons, such as:
They can also be codified or non-codified, in which case they can easily be broken.
The concept of a personal union has only very rarely crossed over from monarchies into republics.
There are currently two personal unions in the world: the 15 Commonwealth realms, who share Charles III as their head of state, and one of the co-princes of Andorra being the President of France.

Monarchies in personal union

Africa

Congo Free State and Belgium

  • Personal union with Belgium from 1885 to 1908, when the Congo Free State became a Belgian colony. The only sovereign during this period was Leopold II, who continued as king of Belgium until his death a year later in 1909.

Asia

Near East

  • During the reign of Sargon II and Senaquerib, Babilonia and Assyria were two reigns connected via the same ruler.

Georgia

Goryeo

King Chungseon of Goryeo reigned as King of Goryeo in 1298 and 1308–1313 and as King of Shenyang or King of Shen from 1307 or 1308 to 1316. At that time, Goryeo had already become a vassal of the Mongol Empire and the Mongol imperial family following the Mongol invasions of Korea and the Goryeo royal family had established strong ties by intermarrying with the Mongol imperial family. Because King Chungseon was a very powerful man during the reign of Külüg Khan, Külüg Khan gave him a new title on top of his kingship of Goryeo, the Prince/King of Shenyang, in 1307 or 1308 specifically mentioned as thanks to his efforts of bringing the Khan to power.
However, he lost his power in the Mongol imperial court after the death of the Külüg Khan. Because the Mongol Empire made Chungseon abdicate the crown of the Goryeo in 1313, the personal union was ended. King Chungsuk, Chungseon's eldest son, became the new King of Goryeo. In 1316, the Mongol Empire made Chungseon abdicate the crown of Shen in favour of Wang Ko, one of his nephews, resulting in him becoming the new King of Shen.
Following Wang Ko's death, Chungmok of Goryeo and Chungjeong of Goryeo were also dual rulers of both Goryeo and Shenyang from 1345-1351.

Europe

Albania

Andorra

Due to Andorra's special government form resulting from the Paréage of 1278, it is a diarchy with co-princes. One of them is the Bishop of Urgell; the other was originally the Count of Foix. It is through this feudal co-prince system that the Principality has entered partial personal union with:
In 1607, the feudal co-prince was Henry IV of France, who issued an edict that his position should be held by the French Head of State. While the new government did not take up the title during the French Revolution, all polities of France since 1806 regardless of their government form have accepted that their head of state is an ex officio co-prince. This led to personal unions with:

Austria

Bohemia

Brandenburg

Catalonia

Croatia

Denmark

Personal union with:

England

Personal union, as Kingdom of England, with:
''1: After 1707, see Great Britain below.''

France

Note: The point at issue in the War of the Spanish Succession was the fear that the succession to the Spanish throne dictated by Spanish law, which would devolve on Louis, le Grand Dauphin — already heir to the throne of France — would create a personal union that would upset the European balance of power; France had the most powerful military in Europe at the time, and Spain the largest empire.

[|Great Britain]

Before 1707, see England and Scotland.
''After 1801, see United Kingdom below.''

Hanover

Holy Roman Empire

Hungary

  • Personal union with Croatia 1102–1918.
  • Personal union with Poland and Bohemia 1305.
  • Personal union with Poland from 1370 to 1382 under the reign of Louis the Great. This period in Polish history is sometimes known as the Andegawen Poland. Louis inherited the Polish throne from his maternal uncle Casimir III. After Louis' death the Polish nobles decided to end the personal union, since they did not want to be governed from Hungary, and chose Louis' younger daughter Jadwiga as their new ruler, while Hungary was inherited by his elder daughter Mary. Personal union with Poland for the second time from 1440 to 1444.
  • Personal union with Naples from 1385 to 1386 under the reign of Charles III of Naples.
  • Personal union with Bohemia, 1419–1439, 1453–1457 and 1490–1918.
  • Personal union with the Archduchy of Austria, 1437–1439, 1444–1457, and 1526–1806.
  • Personal union with the Holy Roman Empire, 1410–1439, 1556–1608, 1612–1740 and 1780–1806.
  • Real union with Austria, 1867–1918 under the reigns of Franz Joseph and Charles IV.

Iceland

Ireland

Italy

León, Aragon, and Castile

Lithuania

Luxembourg

Naples

Navarre

  • Personal union with France from 1285 to 1328 due to the marriage between Philip IV of France and Joan I of Navarre and the reign of their three sons, and from 1589 to 1620 due to the accession of Henry IV, after which Navarre was formally integrated into France.

Netherlands

Norway

  • Sweyn Forkbeard ruled both Norway and Denmark from 999 to 1014. He also ruled England from 1013 to 1014.
  • Cnut the Great ruled both England and Denmark from 1018 to 1035. He also ruled Norway from 1028 to 1035.
  • Personal union with Denmark 1042–1047. Magnus I of Norway, who died of unclear circumstances, ruled both Norway and Denmark.
  • Personal union with Sweden.
  • Personal union with Denmark.
  • Personal union with Sweden.
  • The Kalmar Union with Denmark and Sweden from 1389/97 to 1521/23.
  • Personal union with Denmark.
  • Personal union with Sweden from 1814 to 1905.

Poland

Pomerania

Portugal

Prussia

Romania

Russia

Sardinia

Saxe-Coburg and Saxe-Gotha

In 1826, the newly created Duchy of Saxe-Coburg and Gotha was initially a double duchy, ruled by Duke Ernest I in a personal union. In 1852, the duchies were bound in a political and real union. They were then a quasi-federal unitary state, even though later attempts to merge the duchies failed.

Saxe-Weimar and Saxe-Eisenach

The duchies of Saxe-Weimar and Saxe-Eisenach were in personal union from 1741, when the ruling house of Saxe-Eisenach died out, until 1809, when they were merged into the single duchy of Saxe-Weimar-Eisenach.

Schleswig and Holstein

Duchies with peculiar rules for succession. See the Schleswig-Holstein Question.
The kings of Denmark at the same time being dukes of Schleswig and Holstein 1460–1864.. The situation was complicated by the fact that for some time, the Duchies were divided among collateral branches of the House of Oldenburg. Besides the "main" Duchy of Schleswig-Holstein-Glückstadt, ruled by the Kings of Denmark, there were states encompassing territory in both Duchies. Notably the Dukes of Schleswig-Holstein-Gottorp and the subordinate Dukes of Schleswig-Holstein-Beck, Schleswig-Holstein-Sonderburg-Augustenburg and Schleswig-Holstein-Sonderburg-Glücksburg.

Schwarzburg-Rudolstadt and Schwarzburg-Sondershausen

The duchies of Schwarzburg-Rudolstadt and Schwarzburg-Sondershausen were in personal union from 1909, when Prince Günther of Schwarzburg-Rudolstadt succeeded also to the throne of Schwarzburg-Sondershausen, until 1918, when he abdicated.

Scotland

1: ''After 1707, see Great Britain above. After 1801, see United Kingdom below.''

Sicily

Spain

Sweden

United Kingdom

Historically, the Crown of the United Kingdom was considered to be indivisible. However, as the self-governing dominions of the British Commonwealth gained control over the exercise of the royal prerogative in the 1930s, this concept has evolved so that 'the Crown in right of' each realm and territory acts independently of the other realms and territories. The constitutional conventions established in the Statute of Westminster 1931 which required uniformity in the laws of succession, along with a common format for the royal styles and titles, distinguished the Crown of the Commonwealth realms from a personal union, under which there is no alignment between multiple thrones and different laws of succession may exist but subsequent developments have made the situation more ambiguous.
; Former dominions and Commonwealth realms:
; Current Commonwealth realms

Wales

''After 1542, see England above.''

South America

Brazil

Colombia

Trinidad and Tobago

Guyana

Republics in personal union

Because heads of state and government of republics are ordinarily chosen from within the citizens of the state in question, sovereign republics very rarely share common leaders. A few examples are: