In September 1645 a Parliamentary army under the command of Lord Fairfax and Oliver Cromwell advanced into Somerset, taking Sherborne, Cary and Shepton Mallet before turning to Nunney. Two regiments of soldiers with cannons surrounded the castle on 18 September; when Richard Prater refused to surrender, the cannons opened fire on the north side of the castle, breaching the castle wall. Richard continued to resist, hoisting a flag with a Catholic crucifix on it above the castle to taunt the besiegers, but two days later the garrison surrendered.