Rochester Castle Rochester Castle stands on the east bank of the River Medway in Rochester , Kent , South East England . The 12th - century keep or stone tower , which is the castle ' s most prominent feature , is one of the best preserved in England or France . Located along the River Medway and Watling Street , Rochester was a strategically important royal castle . During the late medieval period it helped protect England ' s south - east coast from invasion . The first castle at Rochester was founded in the aftermath of the Norman Conquest . It was given to Bishop Odo , probably by his half - brother William the Conqueror . During the Rebellion of 1088 over the succession to the English throne , Odo supported Robert Curthose , the Conqueror ' s eldest son , against William Rufus . It was during this conflict that the castle first saw military action ; the city and castle were besieged after Odo made Rochester a headquarters for the rebellion . After the garrison capitulated , this first castle was abandoned . Between 1087 and 1089 , Rufus asked Gundulf , Bishop of Rochester , to build a new stone castle at Rochester . He established the current extent of the castle . Though much altered through the centuries , some parts of Gundulf ' s work survive . In 1127 King Henry I granted the castle to the Bishops of Canterbury in perpetuity . William de Corbeil built the massive keep that still dominates the castle today . Throughout the 12th century the castle remained in the custody of the archbishops . During the First Barons ' War ( 1215 – 1217 ) in King John ' s reign , baronial forces captured the castle from Archbishop Stephen Langton and held it against the king , who then besieged it . The Barnwell chronicler remarked " Our age has not known a siege so hard pressed nor so strongly resisted " . After resisting for just over seven weeks , the garrison surrendered . Although the castle had been greatly damaged , with breaches in the outer walls and one corner of the keep collapsed , it was hunger that eventually forced the defenders ' hand . The castle did not stay under John ' s control for long : in 1216 it was captured by the French Prince Louis , who was the new leader of the baronial faction . John died and was succeeded by his son King Henry III in 1216 ; the next year , the war ended and the castle was taken under direct royal control . 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 . Early history . Castles were introduced to England by the Normans in the 11th century and their construction , in the wake of the conquest of 1066 , helped the Normans secure their new territory . Rochester was an important city , built on the site of a Roman town at the junction of the River Medway and Watling Street , a Roman road . It has long been assumed that the first castle was located next to the river , just outside the south - west corner of the town walls . The conjectural site of the early castle later became known as " Boley Hill " . Archaeologist Tom McNeill has suggested that these earliest castles in England may have been purely military in character , built to contain a large number of troops in hostile territory . According to the Domesday Book of 1086 , the Bishop of Rochester was given land valued at 17s 4d in Aylesford , Kent , in compensation for land that became the site of Rochester Castle . Of the 48 castles mentioned in the survey , Rochester is the only one for which property - owners were reimbursed when their land was taken to build the castle . From the 11th century the castle - guard was a feudal obligation in England . This often took the form of knights garrisoning castles for their lords for a set period . There is no comprehensive list of which castles were owed service in this form , but military historian Cathcart King notes that they seem to have been predominantly high - status castles . Rochester ' s castle - guard consisted of 60 knights ' fees , marking it as a particularly important fortification . 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 sortie s . 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 . After the abandonment of Rochester ' s first castle it was replaced by another on the current site , in the south - west corner of the town walls . Founded between 1087 and 1089 , some parts of the castle survive although it has been much altered by use and reuse in subsequent centuries . William the Conqueror had granted Lanfranc , Archbishop of Canterbury , the manor of Haddenham in Buckinghamshire – which as of the Domesday Survey had an annual income of £40 – for the duration of his life . In turn , the archbishop had granted the manor to Rochester ' s monks , so on the Conqueror ' s death Lanfranc and Gundulf , who was appointed Bishop of Rochester in 1077 , had to appeal for reconfirmation of the original grant from the new king . William Rufus demanded £100 in exchange for confirmation of the grant . The two bishops felt such a sum was beyond their means and sought a compromise . Instead it was agreed that Gundulf would build a new stone castle at Rochester . Initially the two bishops were concerned that the cost would exceed the king ' s original request and that they would be responsible for the castle ' s upkeep . However Henry , Earl of Warwick , convinced them that a castle suitable for the king could be constructed for £40 and that following its completion the castle would be handed over to someone else . The actual cost to Gundulf was £60 . The bishop was a skilled architect and supervised the construction of the Tower of London ' s eponymous White Tower on behalf of William the Conqueror . Gundulf ' s castle was adjacent to Rochester Cathedral . According to archaeologist Oliver Creighton , when castles were positioned close to churches or cathedrals it suggested a link between the two , and in this case both were owned by the Bishop of Rochester . Often the same craftsmen and architects would work on these closely related buildings , leading to similarities in some of their features . Along with Durham and Old Sarum , Rochester is one of the best examples of a closely linked castle and religious building . In 1127 King Henry I granted Rochester Castle to the Archbishop of Canterbury , William de Corbeil , and his successors in perpetuity . He was given permission to build " a fortification or tower within the castle and keep and hold it forever " . Corbeil is responsible for building the great tower or keep that still stands today , albeit in an altered state . The 12th century saw many castles in England rebuilt in stone , an advancement in sophistication of design and technology . Although Rochester had already been given a stone curtain wall by Gundulf , the keep dates from this period . It visually dominated the rest of the castle , towering above its outer walls , and acted as a residence containing the castle ' s best accommodation . A sturdy fortification , it could also serve as a stronghold in the event of military action . Such was the importance of the keep as a symbol of Rochester it was depicted on the town ' s seal in the 13th century . Construction progressed at a rate of about per year . It was probably finished before Corbeil died in 1138 and definitely before 1141 , when Robert , Earl of Gloucester , was imprisoned there during the Anarchy of King Stephen ' s reign . It is likely that after the keep was built there was no further building activity in the 12th century , although the structure was maintained . Though held by the Archbishops of Canterbury under the king , the monarch was still responsible for financially supporting the castle . Continuous records of royal expenditures known as " Pipe rolls " began in the reign of Henry II , and included in the rolls are details of expenditure on Rochester Castle ' s upkeep . During the 12th century , these were generally small figures , but in 1172 – 1173 more than £100 was spent on the castle , coinciding with the rebellion of Henry II ' s sons . Following the fall of Normandy in 1204 to the French forces of King Philip II , King John increased his expenditure on the castles in south - east England in preparation for a possible invasion . Amongst these was Rochester and in 1206 John spent £115 on the castle ' s ditches , keep , and other structures . Under England ' s Angevin kings royal castles in south - east England were invested in to protect the country from invasion ; Rochester was one of the most important . King John . Custody of Rochester Castle remained with the Archbishops of Canterbury until the end of the 12th century . Despite ascending to the throne in 1199 King John did not confirm Hubert Walter as the castle ' s custodian until July 1202 . John may have wished to regain direct control of what was an important castle . The crisis of John ' s rule began in 1212 with the discovery of a plot to overthrow him . Defeat at the Battle of Bouvines in July 1214 marked the end of John ' s ambitions to retake Normandy and exacerbated the situation in England . He returned to England in October and a few months later barons in the north of England were actively challenging his rule . A group of barons renounced their feudal ties to John in May 1215 , and they captured London , Lincoln , and Exeter . John persuaded Stephen Langton , the new Archbishop of Canterbury , to cede control of Rochester Castle to a royal constable , Reginald de Cornhill . Under the terms of the agreement , the castle was to revert to the control of the archbishop at Easter 1215 . This period was later extended to Easter 1216 . Letters patent dated 25 May 1215 requested that other royal constables would take over from Cornhill . The castle would still be returned to the archbishop when the agreement expired or if peace was restored to the kingdom before Easter 1216 . In the meantime , control reverted to Langton whom John had asked to hold the castle " in such a way that by it no ill or harm shall come to us or our kingdom " . John met the rebel barons at Runnymede , and on 19 June 1215 they renewed their vows of fealty . A peace treaty , which later became known as " Magna Carta " , was sealed . Shortly after the treaty the agreement between John and Langton to appoint a royal constable in charge of Rochester Castle was dissolved , returning control to the archbishop . The peace did not last and the First Barons ' War broke out . A group of rebels headed to Rochester to hold the city against John . The events surrounding the rebels ' takeover of the castle are unclear , but contemporary chronicler Ralph of Coggeshall recorded that the king demanded Langton hand over the castle to royal control and the archbishop refused . Although Langton held out against the king ' s demands , the rebels feared he would eventually cave to pressure from the king and seized control of Rochester Castle for themselves . According to Ralph of Coggeshall , this was done with the consent of the castle ' s constable , Reginald de Cornhill , who seems to have switched allegiance from the king to the archbishop after John appointed him as royal constable of the castle . Langton left the country that same month , leaving the castle in the hands of the king ' s enemies . In a letter that year to justiciar Hubert de Burgh John expressed his anger towards Langton , calling him " a notorious traitor to us , since he did not render our castle of Rochester to us in our so great need . " After this point , Rochester Castle was no longer considered to be in the perpetual custody of the archbishops of Canterbury . At the time , John was in south - east England recruiting mercenaries in preparation for his war with the barons . Rochester blocked the direct route to London , which was also held by the rebels . According to Roger of Wendover , the rebels at Rochester were led by William d ' Aubigny , lord of Belvoir . Estimates of the size of Rochester ' s garrison vary , with the chroniclers ' figures ranging from 95 to 140 knights , supported by crossbowmen , sergeants , and others . Hearing the news that the city was in enemy hands , John immediately rode to Rochester and arrived on 13 October . Royal forces had arrived ahead of John and entered the city on 11 October , taking it by surprise and laying siege to the castle . Rochester bridge was pulled down to prevent the arrival of a relief force from London . The siege that followed was the largest in England up to that point , and would take nearly two months . 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 . When the castle ' s outer walls were eventually breached , the defenders retreated to the relative safety of the keep . It too withstood the efforts of the siege engines , and once again John turned to mining to bring down the walls . The mine was dug beneath the south - east corner of the keep . A letter sent from Rochester on 25 November offers insight into the methods of medieval siegecraft . John ordered Hugh de Burgh to " send to us with all speed by day and night forty of the fattest pigs of the sort least good for eating to bring fire beneath the tower " . The wooden props supporting the tunnel dug beneath the keep were set alight to collapse the mine , bringing down one corner of the keep . Still the garrison held out and sought safety behind the stone partition or cross - wall in the keep , abandoning half the building . The Barnwell chronicler remarked that " for such was the structure of the stronghold that a very strong wall separated the half that had fallen from the other " . Conditions within the keep worsened by the day and the garrison were reduced to eating horse flesh . In an attempt to reduce the demand on limited provisions , some members were sent out of the keep , beginning with those least capable of fighting . Some sources record that they had their hands and feet amputated by the besiegers . On 30 November the garrison eventually surrendered and were taken captive . Initially John wanted to execute them all as was the custom of the time when a garrison had forced a long and bloody conflict . Savaric de Mauléon , one of John ' s captains , persuaded the king otherwise , concerned that similar treatment would be shown to royal garrisons by the rebels . Only one person was executed : a crossbowman who had previously been in the service of the king since childhood was hanged . Many of the rebels were imprisoned , sent to royal castles such as Corfe for safe - keeping . Of the siege the Barnwell chronicler wrote , " Our age has not known a siege so hard pressed nor so strongly resisted . . . Afterwards few cared to put their trust in castles " . Prince Louis of France , son of Philip II , was invited by the barons to become the new leader of the rebellion and become king in the event of their victory . In 1216 he arrived in England and captured Rochester Castle ; it is not known how , however , as no documentary evidence recording the event survives . Henry III . John died in 1216 and was succeeded by his nine - year - old son , Henry , with the support of the barons . With no prospect of becoming King of England , Louis returned to France . Rochester Castle was returned to royal control in 1217 . Given the damage incurred during John ' s siege , the castle was in dire need of repairs . Between 1217 and 1237 around £680 were spent on repairs , of which £530 were taken up by work on the keep . In 1225 and 1226 the town walls were enhanced by the addition of a ditch at the cost of £300 . The new ditch enclosed Boley Hill , possibly to deny the position to future aggressors who might attack the castle . Repairs began with the castle ' s outer curtain wall . At the same time a chapel was built within the castle . In 1226 the hall , buttery , and dispensary were repaired . Work probably did not begin on the keep until 1226 . It was mostly repaired by 1227 , but work continued on it until 1232 . During 1230 and 1231 a stone wall dividing the castle ' s enclosure into two parts was built which no longer survives . While attention was paid to making the castle a working fortification , Henry III also funded construction of residential and other buildings . In 1244 , £132 was spent on building a second chapel next to the royal apartments . Stables and an almonry were added in 1248 . The main gatehouse was rebuilt between 1249 and 1250 at a cost of over £120 . Further repairs were carried out on the keep in 1256 , this time costing more than £120 . Later in the decade further attention was paid to the castle ' s defences , possibly in response to Henry III ' s worsening relations with his barons . Henry III ' s reign was in crisis in 1258 . He had recently suffered defeat in Wales , there were agricultural problems leading to a famine , and relations with the pope were worsening . Discontent amongst England ' s magnates led Henry to promise reform , but under continued pressure his authority disintegrated . A royal council of fifteen magnates was formed in June that year , and the rule of the country transferred from the king to the council . With foreign help Henry ' s reign was restored in 1261 as the council were reluctant to start a civil war . Simon de Montfort , Earl of Leicester , raised a rebellion . In 1264 civil war broke out between those loyal to the king and the baronial forces led by de Montfort . Rochester ' s constable in 1264 , Roger de Leybourne , held the castle in support of Henry . John de Warenne , Earl of Surrey , was the garrison ' s co - commander . A baronial army led by Gilbert de Clare , Earl of Hertford , laid siege to the castle on 17 April that year . Having marched from the earl ' s castle to Tonbridge the army attacked from the Rochester side of the river , either the south or west . While the army advanced towards the city the royalist garrison set alight the suburbs . The king ' s hall within the castle was also burned down , although it is unclear why . An army under Simon de Montfort marched from London with the intention of attacking the city from another direction . The earl ' s first two attempts to cross the Medway were fought back , but he was successful on 18 April , Good Friday . The method used is uncertain , although it involved a fire - ship . The smoke may have been used as cover for the rebels , or the ship may have been used to burn the bridge while the army travelled by water . In a co - ordinated attack that had been pre - arranged , the armies of de Montfort and de Clare attacked the city . They entered Rochester in the evening and that night the cathedral was raided . The following day the rebels captured the castle ' s outer enclosure and the royal garrison retreated to the keep . Because the next day was Easter Sunday there was no fighting , though hostilities resumed on the Monday . Siege engines were set up and targeted the keep . As in 1215 the keep proved resistant to missiles , and after a week had not succumbed . According to one contemporary source , the besiegers were about to dig a mine beneath the tower , but the siege was abandoned on 26 April when the earls received news of a relief force led by Henry III and his son , Prince Edward . Later history . Though the garrison had held out within the keep , the rest of the castle had incurred severe damage , but no attempt was made to carry out repairs until the reign of Edward III ( 1327 – 1377 ) . It was noted in 1275 that the castle ' s constables had not only failed to make any effort to repair the structure but had caused further damage : they stole stone from the castle for reuse elsewhere . In 1281 John of Cobham , the constable , was granted permission to pull down the castle ' s hall and chambers which had been left as burnt - out ruins after the 1264 siege . Numerous surveys in the following century bear testament to the castle ' s sorry state and follow its steady decline . A survey from 1340 estimated that repairs would cost around £600 , however another conducted 23 years later stated that it would cost £3 , 333 6s 8d . Natural weathering worsened the condition of the castle , and in 1362 a " great wind " damaged the structure . By 1369 few of the castle ' s buildings still stood : the keep , gatehouses , a hall , kitchen , and stable were all that survived , and even then in a state of ruin . Although it too was in desperate need of repair , the keep was still in use and was the centre of the domestic life at the castle . Between May 1367 and September 1370 repairs costing £2 , 262 were carried out . Records show that sections of the curtain wall were repaired and two mural towers built , one of them replacing a tower on the same site . The towers were positioned north - east of the keep and still stand . Although more work was undertaken between 1370 and 1377 , the year of Edward ' s death , what it consisted of is unknown . The royal apartments built during Henry III ' s reign were never repaired ; it has been suggested this was because by the 14th century , when considerable sums were being spent on repairs elsewhere in the castle , Rochester had fallen out of favour as a royal residence . As the castle ' s importance as a high - status residence waned , its role as a barracks and administrative centre came to the fore . The reign of Richard II ( 1377 – 1400 ) saw the investment of £500 in repairing the castle . This was in part in response to French raids on England ' s southern coast during the Hundred Years War as England ' s fortunes in the conflict worsened . The most significant of these works was the construction of a tower at the north end of the castle , overlooking the bridge over the Medway . Records document the sum of £350 spent on a new tower between 1378 and 1383 , and it mostly likely refers to the one guarding the bridge . Rochester Castle saw fighting for the final time during the Peasants ' Revolt of 1381 . It was besieged and captured by a group of rebels who plundered the castle and released a prisoner . It has been suggested that the £66 10s spent in 1384 – 1388 and the £91 13s spent in 1395 – 1397 may have been partially in response to damage incurred during the revolt . During the reigns of Henry IV ( 1399 – 1413 ) and his successor Henry V ( 1413 – 1422 ) , Rochester Castle was in the guardianship of Sir William Arundel and his brother Richard . The castle was given to Henry V ' s widow , Catherine of Valois , in 1423 as part of her dower to support her financially . She died in 1437 , at which point the castle came under the custodianship of the clerk of the King ' s works . Despite this , there are no records of building work during the 15th century and almost nothing is known about Rochester Castle between then and the second half of the 16th century . The decline of the castle ' s military significance is marked by the leasing of the surrounding ditch , beginning in 1564 at the latest . Between 1599 and 1601 stone from Rochester Castle was reused to build nearby Upnor Castle , an artillery fort . Diarist Samuel Pepys commented on the condition of Rochester Castle , and as early as the 17th century the castle may have acted as a tourist attraction . By this time many castles were in a state of ruin , and Rochester was amongst those in need of repair , although still in use . In 1610 James I granted Sir Anthony Weldon control of the castle . During the English Civil War , Weldon declared for the Parliamentarian cause . The castle did not see fighting during the war , even though the city was captured by Royalists in 1648 ; this may indicate that the castle was not a serviceable fortification by this point . Weldon ' s support for the Parliamentarians may have spared the castle from slighting ( demolition ) in the aftermath , a fate shared by many other castles . Walker Weldon inherited the castle and carried out the destruction of part of the outer wall in the 18th century to sell off the building material ; he had originally intended to dismantle more of the castle , but the plans were abandoned . A drawing from around this time suggests that the cross wall had been removed by this point . While other parts of the castle were dismantled , the two towers in the south - east wall were still being used for accommodation . In 1743 prisoners were held at the castle , probably in huts . Rochester Castle descended through the Weldon family until it was bequeathed to Thomas Blechynden in the 18th century . By 1774 Robert Child was in possession of the castle , and it remained in the possession of his family until 1884 . There were unsuccessful plans in 1780 to reuse Rochester Castle as an army barracks , after the commander of the Royal Engineers for Chatham , Colonel Debbieg , asked the Childs for permission . The castle ruins inspired a painting by artist J . M . W . Turner in the late 18th century , one of his first oil paintings . Turner was renowned for his love of nature and was at the forefront of the picturesque movement , during which such ruins became fashionable . By the 19th century , gardens were created within the castle ' s enclosure . Charles Dickens lived in Rochester and included the castle ruins in " The Pickwick Papers " and " The Mystery of Edwin Drood " . Through the words of one of his characters , Dickens described the castle as a " glorious pile – frowning wall – tottering arches – dark nooks – crumbling stones " . Many of England ' s historic buildings , particularly ruins , have acquired myths and legends , and some are rumoured to be haunted . Rochester is no exception , and is reportedly haunted by a white lady . Dickens is also said to haunt the moat on Christmas Eve . The 19th century saw efforts to preserve the castle . In 1826 repairs were made to the well in the keep . At the same time a survey was carried out by A . W . N . Pugin and he excavated around the keep , investigating how it was built . He descended into the well in a bucket in an unsuccessful search for treasure . Victor Child Villiers , 7th Earl of Jersey , leased the castle to the Corporation of Rochester in 1870 for use as a public park ; when it opened to the public in 1872 , Rochester Castle was presented as a picturesque ruin , with trees planted in the enclosure and the walls overgrown with ivy . In 1884 the Corporation bought the castle for £6 , 572 ( equivalent to £3 . 4 million in 2009 terms ) . Between 1896 and 1904 , George Payne carried out repairs . In the first quarter of the century the gardens acquired a German field gun and a tank from the First World War , and a bandstand , though they were removed by 1961 . Ivy was removed from the keep between 1919 and 1931 and the planting in the castles scaled back . In 1960 the origin of Boley Hill was investigated archaeologically , but the excavations failed to provide firm dating evidence . The castle ' s state was assessed in 1961 , and the cost of repairs estimated at £30 , 000 ( equivalent to £1 . 1 million in 2009 terms ) . The Ministry of Public Building and Works took over care of the castle from the Corporation of Rochester in 1965 . Records of the Ministry ' s conservation work have gone missing , so precisely what was done is unclear . Between 1962 and 1965 the council removed buildings from the castle ' s ditch . Guardianship transferred to English Heritage in 1984 . Since 1995 the City of Rochester has been responsible for daily management of the castle . Descaling at the start of the 21st century contributed to the decay of the keep , and one of the mural towers was in need of maintenance . Due to the decayed state of the keep , public access is restricted and netting has been erected to protect visitors . The possibility of adding floors and a roof to the keep was discussed in the 1970s and 1990s , but there were concerns that a roof would change the climate within the building . The castle is a Scheduled Monument , a " nationally important " historic building and archaeological site which has been given protection against unauthorised change . It is also a Grade I listed building , and recognised as an internationally important structure . The castle is open to the public . Architecture . Little is known about the design of the first castle at Rochester as it has since vanished , and even the exact site is uncertain . It most likely took the form of a motte - and - bailey castle , with a mound and an outer enclosure defended by a timber palisade and earthen banks . Boley Hill has been suggested as the site of the first castle , an outwork reinforcing the castle ' s defences , or an abandoned siege castle like those documented in the 1088 siege . Boley Hill is a natural outcrop of rock , and could have acted as a motte . The castle built by Bishop Gundulf in the late 12th century was enclosed by a stone wall . Situated in the south - west corner of the city , the castle used the remains of the Roman town walls as foundations . The circuit had at least one tower ; it was replaced in the 14th century . The original gateway was radically altered in the 13th or 14th century . From across the River Medway , the twin landmarks of Rochester ' s castle and cathedral would have dominated the medieval landscape , symbolic of the authority of the church and nobility in the period . Most castles were built by secular nobles , but the work by Gundulf and his successor Corbeil provide examples of the role of the church in castle building . According to military historian Allen Brown Rochester ' s keep is " among the finest and oldest in all England " . Since its construction it underwent limited alteration , aside from the rebuilding of one corner , and although now in a state of ruin it remains significantly intact and is considered one of the most important surviving 12th - century keeps in England and France . The keep was richly decorated with hangings and furnishings . Dating from the second quarter of the 12th century , it is Rochester Castle ' s dominant feature . It had a square plan , and measures externally with pilaster buttresses at each corner . The keep was built in the castle ' s southern corner , close to the curtain wall . The primary building material was local Kentish Ragstone , although Caen stone used to face the keep was imported from Normandy . The same material was imported for the Tower of London ' s White Tower in the 11th century . The tops of the turrets rise above the ground , 12 ft above the battlements . Below the latter are rectangular holes , marking where wooden hoarding would have been attached . Though 12 ft thick at the base , the walls of the keep taper to 10 ft at the top . It is the tallest keep in England , and only those at Dover , the Tower of London , Colchester , and Norwich are larger . During John ' s siege of Rochester in 1215 , the south - east corner collapsed ; during Henry III ' s reign it was rebuilt as a cylinder . The windows increase in size higher up the walls , although only the uppermost were decorated . A spiral staircase in the north - east corner provided access to all floors , and another in the south - west corner went from the first floor to the top floor . The north - west corner tower contains small chambers , and the south - east probably had a similar layout before it was rebuilt . Keeps were traditionally built with an entrance at first - floor level , and Rochester ' s follows this pattern . A forebuilding attached to the north side guarded the entrance . A stone staircase began on the west side of the keep before turning and meeting the forebuilding , which could be entered by crossing a drawbridge across a gap wide . There was another entrance in the west of the forebuilding , and at some point a new doorway was knocked through to the keep at the bottom of the drawbridge pit . The original door from the forebuilding into the keep was protected by a portcullis . The stone - built keeps of the 11th century generally had simple plans , with few rooms and an uncomplicated layout . Rochester ' s keep bears testament to a developing complexity , and provides an early example of a keep divided into separate areas for the lord and his retinue . The thickness of the walls allowed rooms to be built into them , as can also be seen at the Hedingham Castle ' s contemporaneous keep , or the slightly later one at Dover . The keep ' s interior is divided for its entire height by a cross wall running east – west . The ground floor was used for storage , with the three storeys above providing accommodation . The first floor probably contained a hall and great chamber , divided by the cross wall . This level may have been the accommodation of the castle ' s constable who looked after it during the owner ' s absence . There is a room called " Gundulf ' s Chamber " built into the thickness of the wall in the north - west corner ; it may well have been the constable ' s private chamber . The second floor contained the keep ' s best accommodation and some of its most elaborate decoration . It is high and surrounded by a gallery in its upper half built into the thickness of the walls . The floor also had a chapel measuring about . At some unknown point in the post - medieval period , a fire gutted the keep , leaving it in its present state without floors or a roof . On the second floor , there are openings in the cross wall , broken by a series of Romanesque columns between round - headed arches . The cross wall carried a well shaft , with a well - head at each floor . The third floor had a second chapel and access to the roof , and may have held additional accommodation . The current entrance in the north - east occupies the approximate location of the main gatehouse constructed by Gundulf and then rebuilt during 1249 – 1250 . It was pulled down in the 1870s when the enclosure was converted into a municipal garden . An engraving from 1735 by the Buck brothers gives some indication of the gatehouse ' s form : the gate was an archway between two towers projecting from the curtain wall . It was reached by a stone causeway across a ditch , rather than a drawbridge . A tower containing a postern gate was located in the north - west corner of the enclosure , built at the close of the 14th century to guard the bridge over the Medway . The tower and postern no longer stands , but 19th - century antiquary and engineer G . T . Clark made some notes on the structure while it was still standing and commented that it had mechanisms to lift supplies for the castle from the river . The western part of the stone outer wall , a stretch facing the river , dates from when Gundulf built the first wall enclosing the castle . In the 19th century a revetment was added to strengthen the decaying wall . Like the keep , it was constructed using Kentish Ragstone . This part of Gundulf ' s wall was thick at the base , narrowing to at the top ; it rose to a height of around . Four embrasure s were added to this part of the wall in the 13th century , although the builders imitated Norman design . At the northern end of the 12th - century stretch of western wall are the remains of a building , probably a hall , dating from the 13th century . Although no longer standing , it is known it had a vaulted undercroft . In the south Gundulf ' s wall survived into the modern period , although has now been dismantled . The current wall is a 19th - century replacement . At the eastern end of this wall , near the southern corner of the castle , is a two - storey rounded tower in diameter dating from the early 13th century . It was built to fill the breach in the curtain wall caused when John ' s army besieged the castle and to reinforce a weak point in the defences . The section from the tower to the location of the former main gatehouse in the north - east dates from about 1367 to 1370 . Two towers were built along the wall , each two storeys high and again using Kentish Ragstone . The one nearest the keep is relatively plain and the northernmost one more elaborate . The latter was intended for use as a residence and in the modern period was converted into a cottage . The wall between these two towers was reduced in the modern period , possibly to give a better view of the cathedral . Apart from the west side , the castle was surrounded by a ditch , much of which has since been filled in . References . Notes Bibliography