There have been 13 British monarchs since the political union of the Kingdom of England and the Kingdom of Scotland on 1 May 1707. The first British monarch was Anne, who reigned between 1707 and 1714; the current monarch is Charles III since his accession in September 2022. Although the informal style of "King of Great Britain" had been in use since the personal union of England and Scotland on 24 March 1603 under James VI and I, the official title came into effect legislatively in 1707 and therefore British monarchs do not include monarchs who held both the title of Monarch of England and Monarch of Scotland at the same time.
On 1 January 1801, the Kingdom of Great Britain and the Kingdom of Ireland merged to create the United Kingdom of Great Britain and Ireland. This later became the United Kingdom of Great Britain and Northern Ireland upon the secession of the Irish Free State (now the Republic of Ireland) in the 1920s. British monarchs have also held various other titles reflecting their claims outside of the United Kingdom, including Elector of Hanover, Emperor of India, and Head of the Commonwealth; they also hold various secondary titles for land within the United Kingdom, such as the Duchy of Lancaster.
