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 1567, Mary was forced to abdicate as Queen of Scots and replaced by her infant son James VI and I, who was brought up as a Protestant and became heir to the English throne. After Elizabeth died in 1603, the two Crowns were held in personal union by James and his Stuart successors but England and Scotland remained separate entities. When James became King of England in 1603, the creation of a unified Church of Scotland and England governed by bishops was the first step in his vision of a centralised, Unionist state. On his accession, he announced his intention