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,
Citation of United Kingdom legislation (OS); before that date, legislation was passed either by the Parliament of England or the Parliament of Scotland. Acts passed by each of these parliaments, except for the Parliament of Scotland, are cited in the same way as pre-1963 Acts of the Parliament of the United Kingdom; i.e., by parliamentary session and chapter number. Acts passed by the Parliament of Scotland are cited by calendar year and chapter number. Note also that Acts of the last session of the Parliament of Great Britain and the first session of the Parliament of the United Kingdom are both cited as "41 Geo.