White Tower ( Tower of London ) The White Tower is a central tower , the old keep , at the Tower of London . It was built by William the Conqueror during the late 11th century , and subsequently extended . History . The castle which later became known as the Tower of London was begun by William the Conqueror in 1066 . It began as a timber fortification enclosed by a palisade . In the next decade work began on the White Tower , the great stone keep that still dominates the castle today . The precise date of the White Tower ' s foundation is unknown , and it is also uncertain how long building took . It is traditionally held that construction began in 1078 . This is because the " Textus Roffensis " records that Gundulf , Bishop of Rochester , oversaw the building work under instruction from William the Conqueror . Dendrochronological evidence suggests construction of the White Tower began in 1075 – 1079 . The archaeology of the standing building suggests there was a pause in construction between 1080 and 1090 – 1093 , although it is unknown why . Gundulf did more than just oversee work and was a skilled architect . Rochester ' s castle and cathedral were rebuilt under his auspices . As the main castle in England ' s capital , the Tower of London was an important royal building . The keep built by Gundulf bears testament to this as it was one of the largest in Christendom . The White Tower was multi - purpose . It was the castle ' s strongest point militarily yet provided accommodation fit for the king and his representatives . In Norman architecture the keep was a symbol of a lord ' s power . The White Tower was probably complete by 1100 at the latest , at which point it was used to imprison Ranulf Flambard , Bishop of Durham . It was probably during Henry II ' s reign ( 1154 – 1189 ) that a forebuilding was added to the south side of the tower to provide extra defences to the entrance , but it has not survived . Henry III ' s relations with his barons were uneasy , and in the 1220s and 1230s he enhanced the castle ' s defences and domestic buildings . Though the work he started may not have been finished within his lifetime , he extended the castle to the north and east , building a new stone wall to enclose the castle . A timber gallery was added to the top of the White Tower , projecting beyond its walls to better defend the base of the tower . Henry also undertook maintenance of the White Tower and it was during his reign that the tradition of whitewashing the building began . In March 1240 the Keeper of the Works at the Tower of London was ordered " to have the Great Tower whitened both inside and out " . Later that year the king wrote to the Keeper , commanding that the White Tower ' s lead guttering should be extended with the effect that " the wall of the tower . . . newly whitened , may be in no danger of perishing or falling outwards through the trickling of the rain " . Henry did not explain his order to whitewash the keep , but may have been influenced by contemporary fashion in Europe to paint prestigious buildings white . He also added decoration to the chapel in the keep , adding stained glass , statues , and paintings . Activity at the castle in the early 14th century declined relative to previous periods . Though the Tower of London was still occasionally used as a residence , by the 1320s the chapel in the White Tower was used to store records . This marked the beginning of the castle ' s diminishing role as a royal residence . The records were briefly removed from the White Tower in 1360 to accommodate the captive French king , John II . It may have been during the reign of Edward III ( 1327 – 1377 ) that a building abutting the south side of the White Tower was created . Built as storage , it may have been part of Edward ' s building programme at the Tower of London which saw its role as a military store come to the fore . The structure no longer survives , but is recorded on plans from 1597 and 1717 . Richard II was imprisoned at the Tower of London and abdicated there in 1399 ; according to tradition , the event took place in the White Tower . In the 1490s a new floor was added to the White Tower , creating extra storage . Architecturally virtually no trace remains of the White Tower ' s forebuilding , although it appears in a manuscript drawing circa 1500 depicting the imprisonment of Charles , Duke of Orléans and was recorded in a plan of 1597 . It was demolished in 1674 . On 17 June that year , during the course of the demolition , bones belonging to two children were discovered beneath the stairs in the forebuilding . It was assumed that they belonged to the Princes in the Tower . The remains were re - interred in Westminster Abbey . The story of the Princes in the Tower is one of the most infamous stories related to the castle . After the death of Edward IV his 12 - year - old son was crowned as Edward V . Richard Duke of Gloucester was declared Lord Protector while the prince was too young to rule . Edward was confined to the Tower of London along with his younger brother , Richard . The Duke of Gloucester was proclaimed King Richard III in July . The princes were last seen in public in June 1483 ; the most likely reason for their disappearance is that they were murdered late in the summer of 1483 . By the Tudor period , the science of fortification had changed to deal with powerful cannons . The new designs , with low angled bastion s , were not emulated at the Tower of London . All the same , some adaptations to use cannon were made ; the changes included adding a timber platform to the top of the White Tower for cannon emplacements . The weight of the guns damaged the roof so that it had to be reinforced . The one documented use of these cannon was during Wyatt ' s rebellion in 1554 and they were ineffective . The Office of Ordnance and Office of Armoury were head - quartered at the Tower of London until the 17th century . Their presence influenced activity at the castle and led to it becoming the country ' s most important military store . In the 1560s two armouries were created in the White Tower and by the reign of Elizabeth I ( 1558 – 1603 ) most of the gunpowder at the Tower was stored in the White Tower . By the last quarter of the 16th century the castle was a tourist attraction with visitors allowed inside despite its use by the Offices of Ordnance and Armoury . Its role in providing storage directly impacted on the White Tower ' s structure and posts were added to support the floors . In 1636 a hole was knocked through the White Tower ' s north wall to ease the movement of provisions . In 1639 – 1640 the White Tower ' s external appearance was changed , with much of its facing material replaced . In 1640 Charles I ordered that the Tower of London should be prepared for conflict . Platforms for cannons were built and 21 installed on top of the White Tower with three additional mortars . Despite the new defences the Parliamentarians captured the Tower of London without the cannon being used . In January 1642 , Charles I attempted to arrest five Members of Parliament . When this failed he fled the city , and Parliament retaliated by removing Sir John Byron , the Lieutenant of the Tower . The Trained Bands had switched sides , and now supported Parliament ; together with the London citizenry , they blockaded the Tower . With permission from the King , Byron relinquished control of the Tower . Parliament replaced Byron with a man of their own choosing , Sir John Conyers . By the time the English Civil War broke out in November 1642 , the Tower of London was already in Parliament ' s control . By 1657 the entire building apart from the chapel was being used to store gunpowder . Storing both gunpowder and government records in the White Tower was not ideal , and there were repeated suggestions in 1620 , 1718 , and 1832 to move the gunpowder to a new location , although the proposals were unsuccessful . By 1661 plans had been proposed to clear an area around the White Tower to safeguard the dangerous material inside . Nothing was done until after the Great Fire of London in 1666 . During the fire it was feared the flames might reach the castle , specifically the White Tower , highlighting the need for safety measures . In the following years a protective wall was built around the White Tower . In the 1670s buildings that had accumulated around the White Tower to provide storage for the Offices of Ordnance and Armoury were pulled down . After this , repairs were carried out on the face of the White Tower . A staircase was also added on the south face , allowing direct access to the records in the chapel . While the Tower of London had been open to visitors since for centuries , it was not until the early 19th century that alterations were made explicitly for visitors . In 1825 a building , the New Horse Armoury , to contain effigies of England ' s kings was constructed against the south of the White Tower . The Gothic revival design of the structure – one of the first purpose - built museums in England – was widely reviled . By the end of the century the effigies and Queen Elizabeth ' s Armoury were distributed in displays in the White Tower . In the mid - 19th century , under the encouragement of Prince Albert , Anthony Salvin undertook a programme of restoration at the castle . In 1858 the White Tower ' s roof was reinforced with iron girders . On 26 January 1885 a bomb in the White Tower damaged some of the displays . The roofs of the White Tower and its turrets were repaired in the 1960s and 1970s . Accumulated dirt was washed from the exterior and the floors inside replaced . Also in this period a staircase was added against the south face of the keep , reopening access through the original entrance . In 1974 , there was a bomb explosion in the Mortar Room in the White Tower , leaving one person dead and 35 injured . No one claimed responsibility for the blast , but the police investigated suspicions that the IRA was behind it . In 1988 , the Tower of London as a whole was added to the UNESCO list of World Heritage Sites , in recognition of its global importance and to help conserve and protect the site . The Tower of London is in the care of Historic Royal Palaces , a charity , and between 2008 and 2011 a £2 million conservation programme was undertaken at the White Tower . Repairs were carried out and the keep was cleaned , removing pollution that was causing damage to the structure . The White Tower is a Grade I listed building , and recognised as an internationally important structure . The Royal Armouries still have displays at the White Tower . Architecture . The White Tower is a keep ( also known as a donjon ) , which was often the strongest structure in a medieval castle , and contained lodgings suitable for the lord — in this case the king or his representative . According to military historian Allen Brown , " The great tower [ White Tower ] was also , by virtue of its strength , majesty and lordly accommodation , the donjon " par excellence " " . One of the largest keeps in the Christian world , the White Tower has been described as " the most complete eleventh - century palace in Europe " . The influences on the White Tower ' s design are unclear . Magnates in northern France had been building stone keeps since the mid - 9th century so the general design was well - established . More specifically the keep of Château d ' Ivry - la - Bataille , built around 1000 , may have been a particularly prominent influence as it included a semi - circular projection in one corner . Allen Brown and P . Curnow suggested that the design may have been based on the now vanished 10th - century keep of Château de Rouen , which belonged to the Dukes of Normandy . At the western corners are square towers , while to the north - east a round tower houses a spiral staircase . At the south - east corner is a larger semi - circular projection which accommodates the apse of the chapel . Excluding its projecting corner towers , the keep measures at the base , and rises to a height of at the southern battlements where the ground is lower . The structure was originally three - storeys high , comprising a basement floor , an entrance level , and an upper floor . The entrance , as is usual in Norman keeps , was above ground ( in this case on the south face ) and accessed via a wooden staircase which could be removed in the event of an attack . The forebuilding added in the 12th century no longer survives . As the building was intended to be a comfortable residence as well as a stronghold , latrines were built into the walls , and four fireplaces provided warmth . The main building material is Kentish rag - stone , though some local mudstone was also used . Although little of it survives , Caen stone was imported from northern France to provide details in the Tower ' s facing , much of it replaced by Portland stone in the 17th and 18th centuries under the direction of architect Inigo Jones . As most of the Tower ' s windows were enlarged in the 18th century , only two original – albeit restored – examples remain , in the south wall at gallery level . The White Tower was terraced into the side of a mound , so the northern side of the basement is partially below ground level . Interior . The purpose of each room is interpreted based primarily on its design . As a result there can be some ambiguity in what individual chambers were used for . Each floor was divided into three chambers , the largest in the west , a smaller room in the north - east , and the chapel taking up the entrance and upper floors of the south - east . As was typical of most keeps , the bottom floor was an undercroft used for storage . One of the rooms contained a well . Although the layout has remained the same since the tower ' s construction , the interior of the basement dates mostly from the 18th century when the floor was lowered and the pre - existing timber vaults were replaced with brick counterparts . The basement is lit through small slits . The sole access to the floor was via the north - east staircase turret . The entrance floor was probably intended for the use of the Constable of the Tower and other important officials . The south entrance was blocked during the 17th century , and not reopened until 1973 . Those heading to the upper floor had to pass through a smaller chamber to the east , also connected to the entrance floor . The crypt of St John ' s Chapel occupied the south - east corner and was accessible only from the eastern chamber . There is a recess in the north wall of the crypt ; according to Geoffrey Parnell , Keeper of the Tower History at the Royal Armouries , " the windowless form and restricted access , suggest that it was designed as a strong - room for safekeeping of royal treasures and important documents " . The upper floor contained a grand hall in the west and residential chamber in the eastboth originally open to the roof and surrounded by a gallery built into the walland St John ' s Chapel in the south - east . The top floor was added in the 15th century , along with the present roof . The absence of domestic amenities such as fireplaces suggest it was intended for use as storage rather than accommodation . In the 17th century lead cisterns were installed on top of the White Tower . St John ' s Chapel . The semi - circular projection in the south - east corner to accommodate St John ' s Chapel is almost unparalleled in castle architecture . The only other keep in England with a similar projection is that of Colchester Castle , the largest in England . St John ' s Chapel was not part of the White Tower ' s original design , as the apsidal projection was built after the basement walls . Due to changes in function and design since the tower ' s construction , except for the chapel little is left of the original interior . The chapel ' s current bare and unadorned appearance is reminiscent of how it would have been in the Norman period . In the 13th century , during Henry III ' s reign , the chapel was decorated with such ornamentation as a gold - painted cross , and stained glass windows that depicted the Virgin Mary and Holy Trinity .