The Fall of Outremer
Siege of Acre Begins
Khalil put a thousand miners to work against each of the major towers. Their work was covered by over a hundred siege engines that hurled not only stones but also pots filled with various flammable substances. Thousands upon thousands of arrows rained down, providing protection for the work of the miners. The work and the bombardment continued day and night.
The walls of Acre were much too strong to take by storm, so mining was the only practical alternative. But the towers were themselves essentially castles and so had also to be taken out. Khalil therefore caused enormous mines to be dug, so that not just an opening but entire sections of the wall might be destroyed, and at multiple points. The Christians recognized the danger and sent out two night sorties in an attempt to demoralize the enemy, but both expeditions failed. After that, the Christians stayed inside the walls.
This went on without cessation for over a month. On 4 May, King Henry arrived with reinforcements—a hundred knights and two thousand foot. It was much too little and much too late. Four days later, the tower of King Hugh was abandoned, and the mines were extended under the English Tower and the Tower of the Countess of Blois.
Then, on 15 May, part of the outer wall of the Tower of King Henry collapsed.