Union of Crowns

A Union of Crowns has occurred many times in history, usually where primogeniture has failed and a country's Crown has passed to the nearest appropriate relative, who might not be of the same nationality, or by marriage.

Examples

• Croatia: A succession crisis following the death of King Demetrius Zvonimir, who had been in personal Union with Hungary, led to the coronation of King Coloman of Hungary as "King of Croatia and Dalmatia" in 1102, a union of those crowns.

• Navarre: Blanche I, Queen of Navarre (d.1229) married Theobald III, Count of Champagne (d.1201) uniting these principalities. Their great-granddaughter Joanna I, Queen of Navarre (d.1304) married Philip IV, King of France, uniting the two kingdoms. Their descendant, Blanche II, Queen of Navarre, married John II, King of Aragon, uniting those two kingdoms. Their descendant, Catherine, Queen of Navarre (d.1517), had a daughter Joan III, Queen of Navarre (d.1572) who married Anthony (d.1562), Duke of Bourbon & Vendome, and King of Navarre (in right of his wife), uniting these crowns.

• Hungary: In 1270 Charles II of Anjou, King of Naples, married Princess Maria (c.1257–25 March 1323), the daughter of Stephen V Arpad, King of Hungary. Her brother Ladislaus IV, King of Hungary died without legitimate issue in 1290. After his death Queen Maria announced her claim to Hungary. Maria's son d.v.p.. Her grandson, Charles I, was crowned King of Hungary and Croatia in early 1301.

• Poland: In 1370 upon the death of Casimir III King of Poland, the crown passed to his sister's son, Louis of Anjou, called 'The Great', King of Hungary and Croatia from 1342, and King of Poland from 1370. This created a Union of Crowns between Hungary and Poland.

• Poland: Jogaila Grand Duke of Lithuania (r.1377-1392) concluded a pact (the Union of Krewo) in 1386, agreeing to accept the Roman Catholic faith, marry the Hungarian heiress of the Polish throne, Jadwiga, younger daughter of Louis of Anjou, 'The Great'. Jadwiga was awarded Poland by her father, and Jogaila now became King of Poland (in right of his wife) taking the Polish names Wladyslaw II Jagiello, thus creating a brief Union of Crowns between Poland and Lithuania.

• Poland: In 1569 the Kingdom of Poland imposed upon Lithuania a Polish-Lithuanian Commonwealth under an elective monarchy. (See that page)

• Poland: The House of Jagiellon failed with the death of King Sigismund II Augustus in 1572, and the crown ultimately passed, via his sister Catherine's marriage in 1562 to John III, King of Sweden, to their son Sigismund III who became King of Poland in 1587 and, upon the death of his father, King of Sweden in 1592, thus creating a Union of Crowns for that generation only.

• England: With the failure of the House of Tudor to produce surviving heirs, upon the death of Elizabeth I the crown of England passed to her second cousin, James VI, King of Scots. Princess Margaret (1489 – 1541), sister of Henry VIII King of England, had married James IV King of Scots (killed in the Battle of Flodden, 1513), and was Regent for their son King James V, grandfather of James VI. This Union of Crowns continues to this day.

• Poland: Frederick Augustus I, Elector of Saxony, was elected King of Poland 1697-1704 and 1709-1733, and his son Frederick Augustus II was Elector of Saxony and King of Poland 1733-1763, a Union of Crowns for 61 years.

• England: Upon the death in 1714 of Queen Anne, sister of Queen Mary II (daughters of King James II of England and Ireland & VII of Scotland), without surviving issue, her second cousin George I, Prince-Elector of Hanover, succeeded to the throne, uniting the crowns of Hanover and Great Britain. This Union of Crowns continued until 1837.