Sapping trenches, cannons and gunpowder explosives were a potent force against fortifications. However, the Siege of Godesberg of 1583 during the Cologne War showed that fortresses could still withstand sapping and explosives to a point. After the attacking force of Ferdinand of Bavaria fired on the fortress with large caliber cannons; this had little impact on the walls. The cannons were firing heavy shot, but the height of the fortress significantly reduced the force of the impact with the walls, which bounced off to little effect, although the fortress dated from the 14th century. To breach the walls, Ferdinand ordered his soldiers to dig into the feldspar supporting the side of the mountain and place an explosive charge. Even after the powder was ignited and a substantial portion of the wall, the gate, and the inner walls were breached, the defenders still held out for three days.