Most of the Oxford army was destroyed at Naseby in June 1645; Charles surrendered to the Scots Covenanters outside Newark-on-Trent in May 1646, followed by the Oxford garrison on 25 June. Besieged by the New Model Army under Sir Thomas Fairfax, Blagge did not capitulate until 27 July when his men were starving and close to mutiny, although the stubborn defence meant he secured good terms. Following the Execution of Charles I in January 1649, he joined Charles II in France, then accompanied him to Scotland in 1651.