 Rochester was besieged for the third time in 1264 during the Second Barons ' War ( 1264 – 1267 ) . The castle 's royal constable , Roger de Leybourne , held Rochester in support of Henry III . Rebel armies led by Simon de Montfort and Gilbert de Clare entered the city and set about trying to capture the castle . Again the castle 's defenders resisted , though this time with a different outcome . After a week , the rebel armies raised the siege in the face of relief from Henry himself . Although the garrison did not surrender , the castle suffered extensive damage that was not repaired until the following century . The castle saw military action for the last time in 1381 when it was captured and ransacked during the Peasants ' Revolt . As Rochester Castle fell out of use its materials were reused elsewhere and custodianship relinquished by the Crown . The castle and its grounds were opened to the public in the 1870s as a park . At various points during the 19th and 20th centuries repairs were carried out . The castle is protected as a Grade I listed building and Scheduled Monument . Today the ruins are in the guardianship of English Heritage and open to the public . 
