History of the formation of the United Kingdom Kingdom of England (which included Wales and controlled Ireland) and the Kingdom of Scotland. The once independent Principality of Wales fell under the control of English monarchs from the Statute of Rhuddlan in 1284. The Union of Crowns in 1603, the accidental consequence of a royal marriage one hundred years earlier, united the kingdoms in a personal union, though full political union in the form of the Kingdom of Great Britain required a Treaty of Union in 1706 and Acts of Union in 1707 (to ratify the Treaty). The Act of Union 1800 united the Kingdom of Great Britain with
Acts of Union 1707 the 1639-1651 Wars of the Three Kingdoms. The 1639–1640 Bishops' Wars confirmed the primacy of the Presbyterian Church of Scotland or kirk and established a Covenanter government in Scotland. The Scots remained neutral when the First English Civil War began in 1642, but grew concerned as to the impact of Royalist victory on Scotland after Parliamentary defeats in the first year of the war. Religious union with England was also seen as the best way to preserve a Presbyterian kirk. The 1643 Solemn League and Covenant provided Scottish military support for the English Parliament in return for a religious union