A personal union consists of two or more entities that are internationally considered separate states, only sharing the same Head of State (and thence also sharing whatever political actions are vested in the Head of State, but no, or at least extremely few, others). It is not to be confused with a federation (like the USA), which is internationally considered a single state.
Personal unions can arise for very different reasons, ranging from near coincidence (a princess who is already married to a king becomes a queen regnant, and their child inherits the crown of both countries) to virtual annexation (where a personal union sometimes was seen as a means of preventing uprisings). They can also be codified (the constitutions of the states clearly express that they shall be joined together) or non-codified (in which case they can easily be broken by e.g. different succession rules).
Because presidents of republics are ordinarily chosen from within the citizens of the state in question, personal unions are almost entirely a phenomenon of monarchies. With the decline of their number during the 20th century, personal unions have become quite uncommon. Where they do exist, most notably between the so-called Commonwealth Realms, they are now mostly ceremonial, as the Governor-General, who is the representative of the Head of State, has only marginal political power.
There is a somewhat grey area between personal unions and federations, and the one has regularly grown into the other. This article is an attempt at listing some historical and contemporary personal unions.
Albania
- Personal union (not universally recognized) with Italy from 1939 to 1946 (when republic was proclaimed)
- Personal union (not universally recognized) with Ethiopia from 1939 to 1941
Andorra
- Partial personal union with France since 1607 (the French president is one of the Heads of State in Andorra)
Antigua and Barbuda
- The Commonwealth Realms, officially a personal union since 1927, presently with Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
- The Commonwealth Realms, officially a personal union since 1927, presently with Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
Austria
Bahamas
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
Barbados
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
- Personal union with Norway from 1380 to 1536 (when Norway was officially incorporated into the Danish kingdom, often called Denmark-Norway)
- The Kalmar Union with Norway and Sweden from 1389 to 1521 (sometimes defunct)
- The kings of Denmark at the same time being dukes of Schleswig and Holstein 1460-1864. (Holstein being part of the Holy Roman Empire)
- Personal union with Iceland from 1918 (broken out of Denmark) to 1944
- Personal union with Ireland from 1541 (when Ireland was raised to the level of a kingdom) to 1707
- Personal union with Scotland from 1603 to 1707 (when they were joined together in the Kingdom of Great Britain)
- Personal union (not universally recognized) with Italy from 1936 to 1941
- Personal union (not universally recognized) with Albania from 1939 to 1941
- Personal union with Russia from 1809 (ceded from Sweden) to 1917
- Partial personal union with Andorra since 1607 (the French president is one of the Heads of State in Andorra)
Grenada
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
Hanover
Holy Roman Empire
- Personal union with Spain from 1519 to 1556
- Personal union with Austria from 1867 to 1918 (the dual monarchy of Austria-Hungary)
- Personal union with Denmark from 1918 (broken out of Denmark) to 1944
- Personal union (not universally recognized) with Ethiopia from 1936 to 1941
- Personal union (not universally recognized) with Albania from 1939 to 1946
Jamaica
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Grenada, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
- Personal union with Poland from 1386 to 1569 (when they were joined together in the Polish-Lithuanian Commonwealth)
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
- Personal union with Sweden from 1319 to 1343
- Personal union with Denmark from 1380 to 1536 (when Norway was officially incorporated into the Danish kingdom, often called Denmark-Norway)
- The Kalmar Union with Denmark and Sweden from 1389 to 1521 (sometimes defunct)
- Personal union with Sweden from 1814 to 1905 (when Norway was ceded from Denmark and entered into a union with Sweden, sometimes called Sweden-Norway)
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
- Personal union with Lithuania from 1386 to 1569 (when they were joined together in the Polish-Lithuanian Commonwealth)
Poland-Lithuania
- Personal union with Sweden from 1592 to 1599
- Personal union with Spain from 1580 to 1640 (under Philip II of Spain, his son and grandson)
- Personal union with Finland from 1809 to 1917
Saint Kitts and Nevis
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
Saint Lucia
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Vincent and the Grenadines, the Solomon Islands, Tuvalu and the United Kingdom
Saint Vincent and the Grenadines
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, the Solomon Islands, Tuvalu and the United Kingdom
- Personal union with the Holy Roman Empire from 1519 to 1556
- Personal union with Portugal from 1580 to 1640 (under Philip II of Spain, his son and grandson)
Schleswig and Holstein
Duchies with peculiar rules for succession.
- 1460 to 1864 were parts or all of the duchies in personal union with Denmark.
Solomon Islands
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Tuvalu and the United Kingdom
Sweden
Main article: Unions of Sweden
- Personal union with Norway from 1319 to 1343
- The Kalmar Union with Denmark and Norway from 1389 to 1521 (sometimes defunct)
- Personal union with Poland-Lithuania from 1592 to 1599
- Personal union with Norway from 1814 to 1905 (sometimes called Sweden-Norway)
Tuvalu
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands and the United Kingdom
- Personal union with Hanover from 1801 to 1837
- Personal union with Ireland from 1922 (broken out) to 1949
- The Commonwealth Realms, officially a personal union since 1927, presently with Antigua and Barbuda, Australia, the Bahamas, Barbados, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, the Solomon Islands and Tuvalu