 It was probably William the Conqueror who gave the city and its castle to Bishop Odo of Bayeux , the king 's half brother . On William 's death in September 1087 his territories were divided between his two sons . Robert , the elder , inherited the title of Duke of Normandy and William Rufus became King of England . A significant number of Norman barons objected to dividing Normandy and England , and Bishop Odo supported Robert 's claim to the English throne . Several others , including the earls of Northumberland and Shrewsbury and the Bishop of Coutances came out in support of Robert . Odo prepared Rochester Castle for war and it became one of the headquarters of the rebellion . Its position in Kent made it a suitable base for raids on London and its garrison could harry William 's forces in the county . William set off from London and marched towards Rochester to deal with the threat . Before he arrived , news reached the king that Odo had gone to Pevensey Castle , which was under the control of Robert , Count of Mortain . William turned away from Rochester and seized Pevensey . The captured Odo was forced to swear to hand over Rochester to William 's men . The king despatched a force with Odo in tow to demand Rochester 's surrender . Instead of yielding , the garrison sallied and captured the entire party . In response William laid siege to the city and castle . Contemporary chronicler Orderic Vitalis recorded that the siege began in May 1088 . Two siege @-@ castles were built to cut off the city 's supply lines and to protect the besiegers from sorties . Conditions within the city were dire : disease was rampant , exacerbated by the heat and flies . The garrison ultimately capitulated and terms were agreed . Odo , Eustace , Count of Boulogne , and Robert de Belleme , son of the Earl of Shrewsbury , were allowed to march away with their weapons and horses but their estates in England were confiscated . This marked the end of the castle 's role in the rebellion , and the fortification was probably abandoned shortly afterwards . The siege @-@ castles were abandoned after the conclusion of the siege and have since vanished . 
