The interregnum of England (and Wales), Scotland, and Ireland started with the execution of Charles I in January 1649 (September 1651 in Scotland) and was decisively ended in July 1660 when his son Charles II was restored to the thrones of the three realms, although he had been already acclaimed king in Scotland since 1650.
The precise start and end of the interregnum, and the social and political events that occurred during the interregnum varied in the three kingdoms and the English dominions.
After the Second English Civil War the leadership of the New Model Army felt deeply betrayed by the King because they thought that while they had been negotiating in good faith he had duplicitously gone behind their backs in making The Engagement with the Scots and encouraging a new civil war. In April 1648 the Grandee of the Army met for a three-day meeting in Windsor Castle. At the end of the meeting the Grandees accepted that it was their duty "to call Charles Stuart, that man of blood, to an account for that blood he had shed, and mischief he had done".
The Army and the Independents conducted "Pride's Purge" of the House of Commons removing their ill-wishers, and created a court for the trial and sentence of King Charles I. At the end of the trial the 59 Commissioners (judges) found Charles I guilty of high treason, as a "tyrant, traitor, murderer and public enemy". He was beheaded on a scaffold in front of the Banqueting House of the Palace of Whitehall on 30 January 1649.
The execution of Charles I ushered in the period known as the Interregnum. The reactions to the regicide and to subsequent events varied considerably between the three Kingdoms and the English Dominions.