On the north exterior wall, near the walled up ‘Door of Excommunication’ is the mark of a cannon ball from the Civil War. Tong Castle was fought over twice. Richard Symons (1617-92), who was a member of the Royalist Army, has this entry in his diary: Satterday, May 17, 1645. His Majestic marched by Tong, com. Salop, a faire church, the windows much broken. A fayre old castle neare this church called Tong Castle.

After the reformation Tong College had fallen into disrepair and probably used as a first line of defence of the castle. A stray cannon ball aimed at the College may have caused the damage. Tong castle itself was badly damaged and burnt down during the first part of the war 1644.