The siege of St Andrews Castle (1546–1547) followed the killing of Cardinal David Beaton by a group of Protestants at St Andrews Castle. They remained in the castle and were besieged by the Governor of Scotland, Regent Arran. However, over 18 months the Scottish besieging forces made little impact, and the Castle finally surrendered to a French naval force after artillery bombardment. The Protestant garrison, including the preacher John Knox, were taken to France and used as galley slaves.