List of British monarchs

There have been 12 monarchs of Great Britain and the United Kingdom (see the Monarchy of the United Kingdom). A new Kingdom of Great Britain was formed on 1 May 1707 with the merger of the Kingdom of England and the Kingdom of Scotland, which had been in personal union under the House of Stuart since 24 March 1603. On 1 January 1801, Great Britain merged with the Kingdom of Ireland to form the United Kingdom of Great Britain and Ireland. After most of Ireland left the union on 6 December 1922, its name was amended on 12 April 1927 to the United Kingdom of Great Britain and Northern Ireland.

House of Stuart (1707–1714)
Queen Anne had been queen of England, Scotland and Ireland since 8 March 1702, and so became Queen of Great Britain upon the Union of England and Scotland.

House of Hanover (1714–1901)
The Hanoverian succession came about as a result of the Act of Settlement 1701, passed by the Parliament of England, which excluded "Papists" (that is, Roman Catholics) from the succession. In return for access to the English plantations in North America and the West Indies, the Hanoverian succession and the Union were ratified by the Parliament of Scotland in 1707.

After the death of Queen Anne with no living children, George I, the son of Sophia of Hanover, granddaughter of James VI of Scotland and I of England through his daughter Elizabeth of Bohemia, was the closest heir to the throne who was not a Roman Catholic.

House of Saxe-Coburg and Gotha (1901–1917)
Although he was the son and heir of Victoria, Edward VII inherited his father's names and is therefore counted as inaugurating a new royal house.

House of Windsor (1917–present)
The house name Windsor was adopted in 1917, during World War I. It was changed from Saxe-Coburg-Gotha because of wartime anti-German sentiment in the United Kingdom.