Personal union

A personal union is a special arrangement where two or more monarchical states share the same ruler, but they keep their own borders, laws, and governments. This is different from a real union, where states share some government services, and from a federation, where a central government connects the states together. In a personal union, each state stays independent and runs itself, even though they have the same monarch.

The idea of a personal union was first described by a German lawyer named Johann Stephan Pütter in 1760. Personal unions can happen for many reasons. For example, a monarch might inherit rule over two different countries through their family, or new countries might choose to keep the same monarch as their former ruler when they become independent.

Today, there are still personal unions in the world. The 15 Commonwealth realms all have Charles III as their head of state. Also, one of the rulers of Andorra is the President of France. These arrangements show how countries can be connected through their leaders while staying separate in many ways.

Monarchies in personal union

Africa

Congo Free State and Belgium

The Congo Free State and Belgium shared the same monarch, Leopold II, from 1885 to 1908. During this time, the Congo Free State became a Belgian colony, and Leopold II continued as king of Belgium until his death in 1909.

Asia

Near East

During the reigns of Sargon II and Senaquerib, the kingdoms of Babilonia and Assyria were ruled by the same monarch.

Georgia

Several Georgian kingdoms, such as Iberia, Colchis, Pontus, Abkhazia, Kakheti, Kartli, Kakheti, Imereti, and Guria, were connected under single monarchs at various points between 300 BCE and the 18th century.

Goryeo

The Korean kingdom of Goryeo shared a monarch with Shenyang in the Mongol Empire from 1308 to 1313 and again from 1345 to 1351. King Chungseon of Goryeo also ruled as King of Shenyang or Shen during this period.

Europe

Albania

The Medieval Albanian Kingdom was in personal union with the Kingdom of Naples from 1272 to 1368 and with the Kingdom of Italy from 1939 to 1943.

Andorra

Andorra has a unique diarchy with co-princes, one of whom is the Bishop of Urgell and the other historically the Count of Foix. This system led to personal unions with the Kingdom of Navarre (1479–1620), the Kingdom of France (1589–1792, 1814–1815, 1815–1830, 1830–1848), and various French states including the First and Second French Empires, and several French Republics.

Austria

Austria entered personal unions with the Lands of the Bohemian Crown (1260–1276, 1306–1307, 1438–1439, 1453–1457, 1526–1918), the Lands of the Hungarian Crown (1437–1439, 1444–1457, 1526–1918), the Austrian Netherlands (1714–1795), the Spanish Empire (1519–1521), the Kingdom of Naples (1714–1735), the Kingdom of Sardinia (1714–1720), the Kingdom of Sicily (1720–1735), the Duchy of Parma (1735–1748), Venetia (1797–1805), the Kingdom of Lombardy–Venetia (1814–1859), and several other territories.

Bohemia

Bohemia had personal unions with Poland (1003–1004, 1296–1306), Hungary (1305), Luxembourg (1313–1378, 1383–1388), Hungary again (1419–1437, 1490–1526), and Austria and Hungary (1438–1439, 1453–1457, 1526–1918).

Brandenburg

Brandenburg was in personal union with the Principality of Ansbach (1415–1440, 1470–1486) and the Duchy of Prussia from 1618 until 1701 when they were consolidated into one government.

Catalonia

Catalonia, as the Principality of Catalonia, was in personal union with the Kingdom of Aragon, the Kingdom of Mallorca, and the Kingdom of Valencia, forming the Crown of Aragon. It later united with the Monarchy of Spain (1516–1714) and the Kingdom of France (1641–1652).

Croatia

Croatia was in personal union with the Kingdom of Hungary from 1102 to 1918.

Denmark

Denmark shared monarchs with Norway, England, the Duchy of Estonia, Sweden, the Duchy of Schleswig, the County/Duchy of Holstein, the County of Oldenburg, the County of Palatinate-Neumarkt, Rügen, the Duchy of Saxe-Lauenburg, and Iceland at various points from 986 to 1944.

England

England was in personal union with Denmark, the Duchy of Normandy, the County of Anjou, much of France, Aquitaine, the Principality of Wales, the Kingdom of France, the Lordship/Kingdom of Ireland, the Monarchy of Spain, the Kingdom of Scotland, the Principality of Orange, and the Dutch Republic at different times from 1013 to 1702.

France

France entered personal unions with the Kingdom of England, the Kingdom of Naples, the Duchy of Milan, the Kingdom of Scotland, the Polish–Lithuanian Commonwealth, the Kingdom of Navarre, Andorra, the Principality of Catalonia, Italy, and the Confederation of the Rhine at various points from 1154 to 1813.

Great Britain

Before 1707, see England and Scotland. Great Britain was in personal union with the Kingdom of Ireland (1707–1801), the Electorate of Hanover (1714–1837), and the Kingdom of Corsica (1794–1796).

Hanover

Hanover was in personal union with Great Britain and Ireland from 1714 to 1801, the United Kingdom from 1801 to 1807 and again from 1814 to 1837, and was merged into the Kingdom of Westphalia from 1807 to 1813 during the Napoleonic Wars.

Holy Roman Empire

The Holy Roman Empire had personal unions with the Kingdom of Sicily (1194–1254), Spain (1519–1556), Hungary (1410–1439, 1556–1608, 1612–1740, 1780–1806), the Kingdom of Naples (1714–1735), the Kingdom of Sardinia (1714–1720), and the Kingdom of Sicily (1720–1735).

Hungary

Hungary was in personal union with Croatia (1102–1918), Poland and Bohemia (1305), Poland (1370–1382, 1440–1444), Naples (1385–1386), Bohemia (1419–1439, 1453–1457, 1490–1918), Austria (1437–1439, 1444–1457, 1526–1806), the Holy Roman Empire (1410–1439, 1556–1608, 1612–1740, 1780–1806), and as a real union with Austria from 1867 to 1918.

Iceland

Iceland was in personal union with Denmark from 1918 to 1944 when it became a republic.

Ireland

Ireland was in personal union with the Kingdom of England (1542–1649, 1660–1707), the Kingdom of Scotland (1603–1649, 1660–1707), the Kingdom of Great Britain (1707–1801), the Electorate of Hanover (1714–1801), and as the Irish Free State and Éire with the United Kingdom (1922–1937, 1937–1949).

Italy

Italy was in personal union with the Kingdom of Albania (1939–1943) and the Ethiopian Empire (1936–1941).

León, Aragon, and Castile

The Kingdom of León, Galicia, and Asturias (914–924), León and Castile (1037–1065, 1072–1230), the Crown of Aragon (Aragon, Catalonia, Valencia; 1162–1714), the Crown of Aragon and Navarre (1076–1134), the Crown of Aragon and Sicily (1412–1516), the Crown of Aragon and Naples (1442–1458, 1504–1516), the Crown of Castile and Burgundy (1506), and Castile and Aragon (1516–1715).

Lithuania

Lithuania was in personal union with the Crown of the Kingdom of Poland (1386–1401, 1447–1492, 1501–1569) before forming the Polish–Lithuanian Commonwealth.

Luxembourg

Luxembourg was in personal union with Bohemia (1313–1378, 1383–1388) and the Netherlands (1815–1890) until William III's death ended the union due to Luxembourg's Salic Law.

Naples

Naples was in personal union with Hungary (1385–1386), the Crown of Aragon (1442–1458, 1504–1516), France (1495, 1501–1504), the Monarchy of Spain (1516–1714), the Holy Roman Empire (1714–1735), and the Kingdom of Sicily (1735–1806).

Navarre

Navarre was in personal union with France from 1285 to 1328 and from 1589 to 1620 before formal integration into France.

Netherlands

The Netherlands was in personal union with the Principality of Orange (1579–1795), England, Scotland, and Ireland (1689–1702), and Luxembourg (1815–1890).

Norway

Norway shared monarchs with Denmark and Sweden at various points from 970 to 1905, including periods under the Kalmar Union (1389/97–1521/23) and the union with Sweden from 1814 to 1905.

Poland

Poland had personal unions with the Duchy of Bohemia (1003–1004), the Kingdom of Bohemia (1296–1306), the Kingdom of Hungary (1305, 1370–1382, 1440–1444), the Duchy of Płock and Wizna (1345–1351, 1381–1382, 1435–1495), the Grand Duchy of Lithuania (1386–1401, 1447–1492, 1501–1569), France (1574–1575), Sweden (1592–1599), the Duchy of Ruthenia (1658), the Electorate of Saxony (1697–1706, 1709–1733, 1734–1763), and the Russian Empire (1815–1831).

Pomerania

Pomerania-Stolp and Pomerania-Stargard were in personal union from 1395–1402 and 1403–1478.

Portugal

Portugal was in personal union with Spain from 1580 to 1640 and with Brazil under Pedro I from March 10 to May 28, 1826.

Prussia

Prussia had personal unions with Brandenburg (1618–1701), the Duchy of Courland and Semigallia (1918), the Principality of Neuchâtel (1707–1806, 1814–1848), and the German Empire (1871–1918).

Romania

Wallachia and Moldavia were in personal union under Alexandru Ioan Cuza from 1859 to 1862.

Russia

Russia was in personal union with the Lordship of Jever (1793–1818), the Grand Duchy of Finland (1809–1917), and Congress Poland (1815–1830, 1831–1915).

Sardinia

Sardinia was in personal union with the Monarchy of Spain (1516–1708), the Holy Roman Empire (1714–1720), and the Duchy of Savoy from 1720.

Saxe-Coburg and Saxe-Gotha

The Duchy of Saxe-Coburg and Gotha was initially a double duchy ruled in personal union by Duke Ernest I from 1826, becoming a political and real union in 1852.

Saxe-Weimar and Saxe-Eisenach

The duchies of Saxe-Weimar and Saxe-Eisenach were in personal union from 1741 until merged into Saxe-Weimar-Eisenach in 1809.

Schleswig and Holstein

The kings of Denmark were also dukes of Schleswig and Holstein from 1460 to 1864, with complex succession rules and divisions among branches of the House of Oldenburg.

Schwarzburg-Rudolstadt and Schwarzburg-Sondershausen

These duchies were in personal union from 1909 until 1918 when Prince Günther abdicated.

Scotland

Scotland was in personal union with the Kingdom of England and Ireland from 1603 to 1707, and with the Principality of Orange and the Dutch Republic from 1689 to 1702.

Sicily

Sicily was in union with the Holy Roman Empire (1194–1254), the Crown of Aragon (1282–1285, 1409–1516), the Monarchy of Spain (1516–1713), the Duchy of Savoy (1713–1720), the Holy Roman Empire again (1720–1734), and the Kingdom of Naples (1735–1806).

Spain

Spain had personal unions with the Archduchy of Austria and Austrian lands (1519–1521), the Holy Roman Empire (1519–1556), the Kingdom of Naples, Sardinia, Sicily, and Milan, the Habsburg and Spanish Netherlands, the Kingdom of England, the Kingdom of Portugal, and the Free and Independent State of Cundinamarca.

Sweden

Sweden was in personal union with Norway (1319–1343/55, 1362–1364), Scania (1332–1360), the Kalmar Union with Denmark and Norway (1389/97–1521/23), Norway (1449–1450), the Crown of the Kingdom of Poland (1592–1599), and Norway again (1814–1905).

United Kingdom

The United Kingdom was in personal union with the Principality of Orange and the Dutch Republic (1689–1702), the Electorate of Hanover (1801–1806), and the Kingdom of Hanover (1814–1837). The Crown was considered indivisible until the Statute of Westminster 1931 allowed dominions to act independently.

Wales

Wales was in personal union with England from 1284 to 1542.

South America

Brazil

Brazil was in personal union with Portugal under Pedro I from March 10 to May 28, 1826.

Colombia

The Free and Independent State of Cundinamarca (modern-day Colombia) was in de iure personal union with Spain from 1810 to 1813, though not recognized by the Spanish Crown.

Trinidad and Tobago

Trinidad and Tobago was in personal union with the United Kingdom from 1962 to 1976.

Guyana

Guyana was in personal union with the United Kingdom from 1966 to 1970.

Republics in personal union

Heads of state in republics are usually chosen from within their own citizens, so it is rare for republics to share leaders. However, there have been a few unique cases. For example, the President of France also serves as a constitutional monarch in Andorra with the title of Co-Prince.

Another example is Napoleon Bonaparte, who was both the First Consul of the French Republic and the President of the Italian Republic from 1802 to 1804. Later, Simón Bolívar held the positions of President of Gran Colombia, Peru, and Bolivia during the fight for independence from Spain.