York has a well known association with gun powder plots, being the birthplace of Guy Fawkes. Another example of the destructive power of 17th century military technology can be seen at St Mary’s Tower, destroyed by an explosion on Sunday 16th June 1644. York was besieged by Parliamentarian armies at the time and troops under the command of the Earl of Manchester tunnelled beneath Bootham and placed a powerful charge beneath the tower. You can see today where the destroyed section of the tower was later rebuilt with a smaller diameter.