Sheffield Castle was a castle in Sheffield, England, constructed at the confluence of the River Sheaf and the River Don, possibly on the site of a former Anglo-Saxon long house, and dominating the early town. A motte and bailey castle had been constructed on the site at some time in the century following the Norman Conquest of England in 1066. This was destroyed in the Second Barons' War, and construction of a second castle, this time in stone, began four years later in 1270. Mary, Queen of Scots was held prisoner in this castle and its associated estates for 14 years between 1570 and 1584. The castle was held by Royalist forces for part of the English Civil War, but was surrendered to the Parliamentarians in 1644 following a short siege; its demolition was ordered soon after, and the castle was razed.