Union of the Crowns create a new "imperial" throne of "Great Britain". England and Scotland continued as autonomous states sharing a monarch with Ireland (with an interregnum in the 1650s during the republican unitary state of the Commonwealth and the Protectorate), until the Acts of Union of 1707 during the reign of the last Stuart monarch, Anne. In August 1503, James IV of Scotland married Margaret, eldest daughter of Henry VII of England, and the spirit of the new age was celebrated by the poet William Dunbar in "The Thrissil and the Rois". The marriage was the outcome of the Treaty of Perpetual Peace,
Unionism in Scotland continued until 1746 and the Jacobite defeat at Culloden. With the Acts of Union 1800, Ireland united with Great Britain into what then formed the United Kingdom of Great Britain and Ireland. The history of the Unions is reflected in various stages of the Union Flag, which forms the flag of the United Kingdom. The larger part of Ireland left the United Kingdom in 1922 however Northern Ireland chose to remain within what is now called the United Kingdom of Great Britain and Northern Ireland. The 300th anniversary of the union of Scotland and England was marked in 2007. The