In the 17th century, Comino served as a place of imprisonment or exile for errant knights. Knights who were convicted of minor crimes were occasionally sentenced to the lonely and dangerous task of manning St. Mary's Tower. During the French blockade of 1798–1800, St. Mary's Tower served as a prison by the Maltese insurgents and their British allies for suspected spies or French sympathizers. In 1799, the insurgents transferred the tower's cannons to blockade batteries to bombard French positions. Insurgent positions armed with cannons taken from Comino included Tas-Samra Battery and Ta' Għemmuna Battery.