Personal union

A personal union is the combination of two or more states that have the same monarch while their boundaries, laws, and interests remain distinct. A real union, by contrast, would involve the constituent states being to some extent interlinked, such as by sharing some limited governmental institutions. Unlike the personal union, in a federation and a unitary state, a central (federal) government spanning all member states exists, with the degree of self-governance distinguishing the two. 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'' (Elements of German Public Law) of 1760.

Personal unions can arise for several reasons, such as:
* inheritance through a dynastic union, e.g. Louis X of France inherited France from his father and Navarre from his mother
* decolonization, ex-colonies install the monarch of the former colonizing power as their own upon becoming independent
* autonomization, e.g. instead of annexing Finland into the Russian Empire, Alexander I of Russia prompted to organize his conquest as a new state and act as its head of state

They can also be codified (i.e., the constitutions of the states clearly express that they shall share the same person as head of state) or non-codified, in which case they can easily be broken (e.g., by the death of the monarch when the two states have different succession laws).

The concept of personal union has almost never crossed over from monarchies into republics, but there have been exceptions.

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.

Americas

Brazil

* Personal union with Portugal, under Pedro I of Brazil (Pedro IV of Portugal), from 10 March to 28 May 1826. Pedro was the Prince Royal of Portugal, Brazil and the Algarves when he declared the independence of Brazil in 1822, becoming its first emperor. When his father ( John VI of Portugal) died, Pedro also became King of Portugal, but abdicated the Portuguese throne 79 days later in favour of his older child Princess Maria da Glória.

Asia

Goryeo

* Personal union with Shenyang in the Mongol-led Yuan dynasty of China (1308–1313; King Chungseon)
** As King of Goryeo (高麗國王) and King of Shenyang (瀋陽王) in 1308–1310
** As King of Goryeo and King of Shen (瀋王) in 1310–1313

King Chungseon reigned as King of Goryeo in 1298 and 1308–1313 and as King of Shenyang or King of Shen from 1307 (according to the ''History of Yuan'') or 1308 (according to '' Goryeosa'') to 1316. At that time, Goryeo had already become a vassal of Yuan dynasty and the Yuan imperial family and the Goryeo royal family had close relationship by marriages of convenience. Because he was a very powerful man during Emperor Wuzong's reign, he could become the King of Shenyang where many Korean people lived in China. However, he lost his power in the Yuan imperial court after the death of the Emperor Wuzong. Because the Yuan dynasty 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 Yuan dynasty made Chungseon abdicate the crown of Shen in favour of Wang Go, one of his nephews, resulting in him becoming the new King of Shen.

Europe

Albania

* Medieval Albanian Kingdom personal union with the Kingdom of Naples (1272–1368)
*Personal union with Kingdom of Italy (1939–1943).

Andorra

Even though France is now a republic with a president and not a monarchy, it has nevertheless been in personal union with the neighbouring nominal monarchy (non-hereditary) of Andorra since 1278.

Austria

* Personal union with Lands of the Bohemian Crown (1260–1276, 1306–1307, 1438–1439, 1453–1457, and 1526–1918).
* Personal union with Lands of the Hungarian Crown (1437–1439, 1444–1457, and 1526–1918).
* Personal union with Austrian Netherlands (1714–1795).
* Personal union with Spanish Empire (1519–1521).
* Personal union with Kingdom of Naples (1714–1735), Kingdom of Sardinia (1714–1720), Kingdom of Sicily (1720–1735), Duchy of Parma (1735–1748), Venetia (1797–1805) and Kingdom of Lombardy–Venetia (1814–1859)
* Personal union with Kingdom of Slavonia (1699–1868), Kingdom of Serbia (1718–1739), Kingdom of Galicia and Lodomeria (1772–1918), Duchy of Bukovina (1774–1918), New Galicia (1795–1809), Kingdom of Dalmatia (1797–1805 and 1814–1918) and Bosnia and Herzegovina (1878/1908–1918).

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 Principality of Ansbach from 1415 to 1440 and 1470 to 1486.
* 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 I consolidated them into one government.

Croatia

* Personal union with the Kingdom of Hungary 1102–1918

Denmark

* Personal union with Norway (986–995, 1000–1014, 1028–1035, 1042–1047, 1380–1397, 1397–1523 ( Kalmar Union) and 1524–1814 ( Denmark–Norway)).
* Personal union with England (1013–1014, 1018–1035 (North Sea Empire) and 1040–1042).
* Personal union with Sweden (1397–1523 ( Kalmar Union)).
* Personal union with Duchy of Schleswig (1086–1364, 1460–1864) and County/Duchy of Holstein (1460–1864).
* Personal union with County of Oldenburg (1667–1773)
* Personal union with Duchy of Saxe-Lauenburg (1814–1864)
* Personal union with Iceland (1918–1944).

England

* Personal union, as Kingdom of England, with Denmark (1013–1014, 1018–1035 (North Sea Empire) and 1040–1042).
* Personal union, as Kingdom of England, with Duchy of Normandy (1066–1087, 1106–1144, 1154–1204/1259).
* Personal union, as Kingdom of England, with the County of Anjou (1154–1204).
* Personal union, as Kingdom of England, with much of France (Angevin Empire) (1154–1214).
* Personal union, as Kingdom of England, with Aquitaine (1154–1453).
* Personal union, as Kingdom of England, with Principality of Wales (1284–1542).
* Personal union, as Kingdom of England, with Kingdom of France (1422–1453). See also: Dual monarchy of England and France.
* Personal union, as Kingdom of England, with Lordship of Ireland (1171–1542) and Kingdom of Ireland (1542–1649, 1660–1707).
* Personal union, as Kingdom of England, with Kingdom of Spain (1556–1558).
* Personal union, as Kingdom of England, with Kingdom of Scotland (1603–1649, 1660–1707).¹
* Personal union, as Kingdom of England, with Principality of Orange (1689–1702).

''¹: After 1707, see Great Britain below.''

France

* Personal union, as part of the Angevin Empire, with the Kingdom of England (1154–1214).
* Personal union with the Kingdom of England (1422–1453). See also: Dual monarchy of England and France.
* Personal union with the Kingdom of Naples under the rule of Charles VIII (1495) and Louis XII (1501–1504).
* Personal union with the Duchy of Milan under the rule of Louis XII (1499–1500 and 1500–1512) and Francis I (1515–1521 and 1524–1525).
* Personal union with the Kingdom of Scotland under the rule of Francis II (1559–1560).
* Personal union with the Polish–Lithuanian Commonwealth under the rule of Henry III (1574–1575).
* Personal union with the Kingdom of Navarre (1284–1328 and 1589–1620).
* ''Partial'' personal union with Andorra since 1607 (the French head of state is one of the heads of state in Andorra)
* Personal union under Napoleon with Italy and the Confederation of the Rhine.

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.

Georgia

* Kingdom of Iberia and Colchis were connected power of the monarch in 300–90 years BC ( Pharnavazid dynasty).
* Kingdom of Pontus and Colchis were connected power of the monarch in 109 BC–64 AD.
* 1000–1010 Kingdom of Abkhazia and Iberia ruled by Bagrat III. In 1010 it united (together with the annexed Kakheti kingdom) into a single Kingdom of Georgia.
* Kingdom of Kakheti and Hereti were connected power of the monarch in 1020s–1104.
* Principality of Mingrelia and Principality of Abkhazia in the 1557–1660 years under the rule of the House of Dadiani
* Kingdom of Kartli