 Boley Hill to the south of the castle may have been used as John's headquarters during the siege. According to the Barnwell chronicler, five siege engines hurled a barrage of stones at the castle's wall day and night. These were supported by missiles from smaller bows and crossbows. Though the Barnwell chronicler claimed they smashed a hole in the castle's outer walls, Roger of Wendover asserted they were ineffective and that John turned to other methods to breach the defences. A letter dated 14 October indicates John was preparing to undermine the castle's walls. He wrote to Canterbury, asking for the production "by day and night of as many picks as you are able" and that they be sent to Rochester. On 26 October a relief force of 700 horse was sent from London. They turned back before arriving, perhaps because they heard the king was advancing to meet them.
