The Citadel is situated on the western edge of Jerusalem; its location was determined by earlier fortifications on the site and its topographic elevation. The current structure is a composition of Ayyubid, Crusader, Mamluk, and Ottoman constructions, in addition to the ancient Roman fortification. However, large portions of the contemporary structure date from the Mamluk period, with some additions from the rebuilding of the city walls during the Ottoman period.
The plan consists of five towers connected with fortification walls built in an irregular quadrilateral plan oriented east-west. In the middle of the courtyard is the excavation of early Roman city walls, which cross the yard from its southeast corner to the northeast corner. Two outworks to the east and west of the main fortification walls were built at a later date. The entire structure is surrounded by a moat crossed by a single bridge leading to the main entrance.
An outer gate, reached by two sets of stairs, marks the eastern entrance. A wooden bridge leads to an open outdoor space that was presumably used as an open-air mosque. There is a freestanding pointed-arched mihrab to support this assumption. A circular cartouche set at the keystone of the mihrab contains Arabic text in praise of Sultan Sulaiman. The outdoor space has an irregular plan determined by the alignment of the barbican.
A stone bridge supported on two pointed arches connects the open-air mosque to the inner gate. Small ashlar masonry is used in the construction of the stone bridge spanning the ditch leading to the entrance. The portal consists of a tall pointed arch with a second shorter pointed arch with the same width set within it. In the space between the two points of the two arches is set an inscription marking the restoration by Sultan Sulaiman in 1531-32.
The entry sequence bends westward and again southward into a hexagonal hall. The chamber is topped by a shallow domical vault with an oculus in its center and covered by a raised diminutive dome. The courtyard of the Citadel and the so-called Tower of David, the northeast tower, are accessed from the hexagonal hall.
The base of the northeast tower of the Citadel is built of large, heavy masonry dating from the time of King Herod (1st century BCE). Layers of later constructions and smaller masonry make up the rest of the tower. The northeast tower is accessed by means of a stair leading to the roof of the hexagonal hall. From the roof, the two-storey eastern tower can also be reached. The one storey southeast tower can be reached by a wall-walk extending from the eastern tower southward. Along the south wall of the Citadel, the wall-walk continues, connecting the southeast tower to the southwest corner, which contains a mosque and its minaret attached to a comparatively small tower. On the outside, the southwestern tower is marked by machicolations on each side of the corner. The wall-walk continues from the southwest corner along the western wall towards the two-storey northwest tower, which has three machicolations.
A dedication inscription in Turkish, dating from 1655, is found at the base of the cylindrical minaret. Three moulded string courses divide the minaret into three storeys accessed by a spiral staircase within its core. A square base with a doorway in its south side gives access to the minaret resting above. The minaret is adjacent to the mosque built in 1310-11 by Sultan al-Nasir during the Mamluk period. The long rectangular plan of the mosque aligned east-west is at the top storey of a heavily fortified tower structure. Its interior consists of a series of vaults and an ornate mihrab and pulpit. The present mosque is the result of at least three phases of construction: one Mamluk (1310-11) and two Ottoman: 1532 (Sultan Sulaiman) and 1908-9 (Sultan abd al-Hamid). An inscription found in the mosque records the construction of a mosque by Sultan al-Nasir; however, it is not in its original location.
The earliest components of the Citadel are at bedrock and date to the eighth century BC. Various ancient phases of construction have been identified; however, these ancient remains belong to city walls rather than to a fortress structure. Apart from the city walls, the Herodian tower the only major structure on the site until a Crusader-period structure was built on the site. The foundation of the Citadel followed in the Ayyubid period; major building activity began after the Ayyubid conquest of Jerusalem in 1187, followed by rebuilding during the Mamluk period.
The exact location of Ayyubid period constructions are uncertain. However, inscriptions and historical descriptions dating from that period speak of various construction projects related to the Citadel, including the building of a new tower and the restoration of walls. A moat from the period was dug around the Citadel as part of Salah al-Din's program to refortify the city. The Citadel was dismantled in 1219 to prevent its being utilized by the Crusaders. The structure remained damaged and ruined until the fourteenth century during the reign of Mamluk Sultan al-Nasir.
The structure was rebuilt in 1310, which makes the present Citadel a mostly Mamluk building. Besides the inscription from 1310 found in the mosque, a dedication inscription from the same date was located above the main entrance, but was then lost after it was last documented in 1894. The fabric of the outer walls consists of pre-existing built sections in addition to remains from the Ayyubid period, but its overall construction style is early Mamluk. The Citadel, according to historical records, received special attention and continued to be well intact during the Mamluk period, although the city walls were heavily damaged. While the Citadel lost its military usefulness by the end of the Mamluk period, it maintained a symbolic importance, which was then reinforced by the actions of Ottoman Sultan Sulaiman the Magnificent in the early sixteenth century.
Sultan Sulaiman's repair project for the Citadel had both a functional and a symbolic value. It was meant to establish the Ottoman presence in the city, as well as to garrison the Ottoman army. According to the historian van Berchem, the rebuilding project of the city walls, including the Citadel, took place between 1537-40. As the Ottoman Empire began losing its grip on its provinces, the Citadel suffered no further heavy damage, even though it was used in the eighteenth and nineteenth centuries during various popular uprisings. During both the French Invasion by Napoleon and the Egyptian Occupation by Muhammad Ali, the Citadel was used by the inhabitants of the city as a defense structure for storing weapons and gunpowder. Architecturally speaking, the structure has changed little since Sulaiman's repairs. The structure ceased its military function in the twentieth century; currently it functions as a museum for the city of Jerusalem, and is referred to as the Tower of David.
Hawari, Mahmoud. "The Citadel In The Ottoman Period: An Overview." In Ottoman Jerusalem: The Living City 1517-1917, edited by S.Auld & R.Hillenbrand, 493-518. London: Altajir World of Islam Trust, 2000.
Hillenbrand, Robert. The Architecture of Ottoman Jerusalem: An Introduction, 19-32. London: Altajir World of Islam Trust, 2002.