The Tower of London, officially His Majesty's Royal Palace and Fortress of the Tower of London, is a historic citadel and castle on the north bank of the River Thames in London, England. It lies within the London Borough of Tower Hamlets, which is separated from the eastern edge of the square mile of the City of London by the open space known as Tower Hill. It was founded toward the end of 1066 as part of the Norman Conquest. The White Tower, which gives the castle its name, was built by William the Conqueror in 1078 and was initially a resented symbol of oppression. A grand palace early in its history, it served as a royal residence. The Tower is a complex of several buildings set within two concentric rings of defensive walls and a moat. There were several phases of expansion, mainly under kings Richard I, Henry III, and Edward I in the 12th and 13th centuries.
The Tower of London was besieged several times, and controlling it has been important to controlling the country. The Tower has served as an armoury, a treasury, a menagerie, the home of the Royal Mint, a public record office, and the home of the Crown Jewels of England. From the early 14th century until the reign of Charles II in the 17th century, the monarch would traditionally prepare for several nights at the Tower, and lead a procession from there to Westminster Abbey for their coronation. In the late 15th century, the Princes in the Tower were housed at the castle when they mysteriously disappeared, presumed murdered. Under the Tudors, the Tower was used less as a royal residence, and despite attempts to refortify and repair the castle, its defences lagged behind developments to deal with artillery.
The zenith of the castle's use as a prison was the 16th and 17th centuries, when many figures who had fallen into disgrace, such as Elizabeth I before she became queen, Sir Walter Raleigh, and Elizabeth Throckmorton, were held within its walls. This use has led to the phrase "sent to the Tower". Despite its enduring reputation as a place of torture and death, popularised by 16th-century religious propagandists and 19th-century writers, only seven people were executed within the Tower before the world wars of the 20th century. Executions were more commonly held on Tower Hill to the north of the castle, with 112 occurring there over a 400-year period. In the latter half of the 19th century, institutions such as the Royal Mint moved out of the castle to other locations, leaving many buildings empty. Anthony Salvin and John Taylor took the opportunity to restore the Tower to what was felt to be its medieval appearance.
In the First and Second World Wars, the Tower was again used as a prison and witnessed the executions of 12 men for espionage. After the Second World War, damage caused during the Blitz was repaired, and the castle reopened to the public. Today, the Tower of London is the country's ninth most popular tourist attraction, with 2,817,852 visitors in 2025. Under the ceremonial charge of the Constable of the Tower, operated by the Resident Governor of the Tower of London and Keeper of the Jewel House, and guarded by the Yeomen Warders, the property is cared for by the charity Historic Royal Palaces and is protected as a World Heritage Site.
Architecture
Layout
The Tower's strongest and most impressive defences overlooked Saxon London, which archaeologist Alan Vince suggests was deliberate. It would have visually dominated the surrounding area and stood out to traffic on the River Thames. The castle is made up of three "wards", or enclosures. The innermost ward contains the White Tower and is the earliest phase of the castle. Encircling it to the north, east, and west is the inner ward, built during the reign of Richard I (1189–1199). Finally, there is the outer ward which encompasses the castle and was built under Edward I. Although there were several phases of expansion after William the Conqueror founded the Tower of London, the general layout has remained the same since Edward I completed his rebuild in 1285.
The castle encloses an area of almost 12 acres (4.9 hectares) with a further 6 acres (2.4 ha) around the Tower of London constituting the Tower Liberties – land under the direct influence of the castle and cleared for military reasons. The precursor of the Liberties was laid out in the 13th century when Henry III ordered that a strip of land adjacent to the castle be kept clear. Despite popular fiction, the Tower of London never had a permanent torture chamber, although the basement of the White Tower housed a rack in later periods. Tower Wharf was built on the bank of the Thames under Edward I and was expanded to its current size during the reign of Richard II (1377–1399).
White Tower
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 R. Allen Brown, "The great tower [White Tower] was also, by virtue of its strength, majesty and lordly accommodation, the donjon par excellence". As 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 White Tower, not including its projecting corner towers, measures 36 by 32 metres (118 by 105 ft) at the base, and is 27 m (90 ft) high at the southern battlements. The structure was originally three storeys high, with a basement, an entrance level above, 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. 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. 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. At the western corners of the building are square towers, while to the north-east a round tower houses a spiral staircase. At the south-east corner there is a larger semi-circular projection which accommodates the apse of the chapel. 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 ragstone, although some local mudstone was also used. Caen stone was imported from northern France to provide details in the Tower's facing, although little of the original material survives as it was replaced with Portland stone in the 17th and 18th centuries. Reigate stone was also used as ashlar and for carved details. Its location, in the lower courses of the building and at higher levels corresponding to a building break, suggest it was readily available and may have been used when access to Caen stone was restricted. 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 the gallery level.
The tower was terraced into the side of a mound, so the northern side of the basement is partially below ground level. 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 entrance floor was probably intended for the use of the Constable of the Tower, Lieutenant of the Tower of London 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 east – both originally open to the roof and surrounded by a gallery built into the wall – and St John's Chapel in the south-east. The top floor was added in the 15th century, along with the present roof. 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 the Holy Trinity.
Innermost ward
The innermost ward encloses an area immediately south of the White Tower, stretching to what was once the edge of the River Thames. As was the case at other castles, such as the 11th-century Hen Domen, the innermost ward was probably filled with timber buildings from the Tower's foundation. Exactly when the royal lodgings began to encroach from the White Tower into the innermost ward is uncertain, although it had happened by the 1170s. The lodgings were renovated and elaborated during the 1220s and 1230s, becoming comparable with other palatial residences such as Windsor Castle. Construction of Wakefield and Lanthorn Towers – located at the corners of the innermost ward's wall along the river – began around 1220. They probably served as private residences for the queen and king respectively.
The earliest evidence for how the royal chambers were decorated comes from Henry III's reign: the queen's chamber was whitewashed, and painted with flowers and imitation stonework. A great hall existed in the south of the ward, between the two towers. It was similar to, although slightly smaller than, that also built by Henry III at Winchester Castle. Near Wakefield Tower was a postern gate which allowed private access to the king's apartments. The innermost ward was originally surrounded by a protective ditch, which had been filled in by the 1220s. Around this time, a kitchen was built in the ward. Between 1666 and 1676, the innermost ward was transformed and the palace buildings removed. The area around the White Tower was cleared so that anyone approaching would have to cross open ground. The Jewel House was demolished, and the Crown Jewels moved to Martin Tower.
Inner ward
The inner ward was created during Richard the Lionheart's reign, when a moat was dug to the west of the innermost ward, effectively doubling the castle's size. Henry III created the ward's east and north walls, and the ward's dimensions remain to this day. Most of Henry's work survives, and only two of the nine towers he constructed have been completely rebuilt. Between the Wakefield and Lanthorn Towers, the innermost ward's wall also serves as a curtain wall for the inner ward. The main entrance to the inner ward would have been through a gatehouse, most likely in the west wall on the site of what is now Beauchamp Tower. The inner ward's western curtain wall was rebuilt by Edward I. The 13th-century Beauchamp Tower marks the first large-scale use of brick as a building material in Britain, since the 5th-century departure of the Romans. The Beauchamp Tower is one of 13 towers that stud the curtain wall. Clockwise from the south-west corner they are: Bell, Beauchamp, Devereux, Flint, Bowyer, Brick, Martin, Constable, Broad Arrow, Salt, Lanthorn, Wakefield, and the Bloody Tower. While these towers provided positions from which flanking fire could be deployed against a potential enemy, they also contained accommodation. As its name suggests, Bell Tower housed a belfry, its purpose to raise the alarm in the event of an attack. The royal bow-maker, responsible for making longbows, crossbows, catapults, and other siege and hand weapons, had a workshop in the Bowyer Tower. A turret at the top of Lanthorn Tower was used as a beacon by traffic approaching the Tower at night.
As a result of Henry's expansion, St Peter ad Vincula, a Norman chapel which had previously stood outside the Tower, was incorporated into the castle. Henry decorated the chapel by adding glazed windows, and stalls for himself and his queen. It was rebuilt by Edward I at a cost of over £300 and again by Henry VIII in 1519; the current building dates from this period, although the chapel was refurbished in the 19th century. Immediately west of Wakefield Tower, the Bloody Tower was built at the same time as the inner ward's curtain wall, and as a water-gate provided access to the castle from the River Thames. It was a simple structure, protected by a portcullis and gate. The Bloody Tower acquired its name in the 16th century, as it was believed to be the site of the murder of the Princes in the Tower. Between 1339 and 1341, a gatehouse was built into the curtain wall between Bell and Salt Towers. During the Tudor period, a range of buildings for the storage of munitions was built along the inside of the north inner ward. The castle buildings were remodelled during the Stuart period, mostly under the auspices of the Office of Ordnance. In 1663, just over £4,000 was spent building a new storehouse (now known as the New Armouries) in the inner ward. Construction of the Grand Storehouse north of the White Tower began in 1688, on the same site as the dilapidated Tudor range of storehouses; it was destroyed by fire in 1841. The Waterloo Block, a former barracks in the castellated Gothic Revival style with Domestic Tudor details, was built on the site and remains to this day, housing the Crown Jewels on the ground floor.