Monarchy of Ireland and Ireland in a personal union. The Union of the Crowns in 1603 expanded the personal union to include Scotland. The personal union between England and Scotland became a political union with the enactments of the Acts of Union 1707, which created the Kingdom of Great Britain. The crowns of Great Britain and Ireland remained in personal union until it was ended by the Acts of Union 1800, which united Ireland and Great Britain into the United Kingdom of Great Britain and Ireland from January 1801 until December 1922. After that date, most of Ireland left the United Kingdom to
Acts of Union 1800 Acts of Union 1800 The Acts of Union 1800 (sometimes erroneously referred to as a single Act of Union 1801) were parallel acts of the Parliament of Great Britain and the Parliament of Ireland which united the Kingdom of Great Britain and the Kingdom of Ireland (previously in personal union) to create the United Kingdom of Great Britain and Ireland. The acts came into force on 1 January 1801, and the merged Parliament of the United Kingdom had its first meeting on 22 January 1801. Both acts remain in force, with amendments, in the United Kingdom of Great Britain and