The history of the United Kingdom as a unified sovereign state began in 1707 with the political union of the kingdoms of England and Scotland, into a United Kingdom of Great Britain.[note 1] of this new state the historian Simon Schama said: What began as a hostile merger would end in a full partnership in the most powerful going concern in the world... it was one of the most astonishing transformations in European history. The Act of Union 1800 added the Kingdom of Ireland to create the United Kingdom of Great Britain and Ireland. Following the partition of Ireland and the independence of the Irish Free State in 1922, which left Northern Ireland as the only part of the island of Ireland within the United Kingdom of Great Britain and Northern Ireland.
- The terms United Kingdom and United Kingdom of Great Britain were used in the Treaty of Union and the Act of Union 1707. However, the actual name of the new state was Great Britain. The name Great Britain (then spelled Great Brittaine) was first used by James VI/I in October 1604, who indicated that henceforth he and his successors would be viewed as Kings of Great Britain, not Kings of England and Scotland. However the name was not applied to the state as a unit; both England and Scotland continued to be governed independently. Its validity as a name of the Crown is also questioned, given that monarchs continued using separate ordinals (e.g., James VI/I, James VII/II) in England and Scotland. To avoid confusion, historians generally avoid using the term King of Great Britain until 1707 and instead to match the ordinal usage call the monarchs kings or queens of England and Scotland. Separate ordinals were abandoned when the two states merged in accordance with the 1707 Acts of Union, with subsequent monarchs using ordinals apparently based on English not Scottish history (it might be argued that the monarchs have simply taken the higher ordinal, which to date has always been English). One example is Queen Elizabeth II of the United Kingdom, who is referred to as being "the Second" even though there never was an Elizabeth I of Scotland or Great Britain. Thus the term Great Britain is generally used from 1707.
- New Act of Union would strengthen UK, says Fabricant BBC News, accessed 1 September 2013
- title=Britannia Incorporated |series=A History of Britain|serieslink=Simon Schama's A History of Britain|credits=Simon Schama (presenter) |network=BBC One|airdate=22 May 2001|number=10|minutes= 3}}