The Acts of Union refer to two acts of Parliament, one by the Parliament of Scotland in March 1707, followed shortly thereafter by an equivalent act of the Parliament of England. They put into effect the international Treaty of Union agreed on 22 July 1706, which politically joined the Kingdom of England and Kingdom of Scotland into a single "political state" named Great Britain, with Queen Anne as its sovereign. The English and Scottish acts of ratification took effect on 1 May 1707, creating the new kingdom, with its parliament based in the Palace of Westminster.
The two countries had shared a monarch since the "personal" Union of the Crowns in 1603, when James VI of Scotland inherited the English throne from his cousin Elizabeth I to become (in addition) 'James I of England', styled James VI and I. Attempts had been made to try to unite the two separate countries, in 1606, 1667, and in 1689 (following the Glorious Revolution in 1688, and subsequent deposition of James II of England by his daughter Mary and her husband William of Orange), but it was not until the early 18th century that both nations via separate groups of English and Scots Royal Commissioners and their respective political establishments, came to support the idea of an international "Treaty of political, monetary and trade Union", albeit for different reasons.