There have been 12 monarchs of Great Britain and the United Kingdom.
Kingdom of Great Britain
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.
Queen Anne of England
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.
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.
The Formation of the United Kingdom of Great Britain and Ireland
On 1 January 1801, Great Britain merged with the Kingdom of Ireland to form the United Kingdom of Great Britain and Ireland. The union came into effect on 1 January 1801.
The Acts of Union 1800 (sometimes called the Acts of Union 1801) were two complementary Acts, namely:
- The Union with Ireland Act 1800 (39 & 40 Geo. 3 c. 67), an Act of the Parliament of Great Britain, and
- The Act of Union (Ireland) 1800 (40 Geo. 3 c. 38), an Act of the Parliament of Ireland.
Passed on 2 July 1800 and 1 August 1800 respectively, the twin Acts united the Kingdom of Great Britain and the Kingdom of Ireland to create the United Kingdom of Great Britain and Ireland.
The United Kingdom of Great Britain and Northern 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.