arcade of twelve Corinthian marble columns, set in threes between four large rectangular piers. At the top of the drum, sixteen colored glass windows light the central space. Surrounding the circle is an octagonal, marble-flagged, 30-foot-high (9-meter) ambulatory of twenty-four piers and columns, reached from outside through four doorways with porticoes facing the cardinal directions. The ambulatory is screened from the sanctuary by half-height walls. The columns and most of the capitals were quarried from older buildings. The marble-faced outer walls of the building also describe an octagon; each side is about 60 feet (18 meters) long. Inside and outside, the Dome of the Rock was enriched with marble columns and facings and floral patterns of mosaic. The total effect must have been awesome: “thousands of lights … supplemented the meagre illumination from the windows, making the mosaics glitter like a diadem crowning a multitude of columns and marble-faced piers around the sombre mass of the black rock surmounted, by the soaring void of the dome” (Ettinghausen and Grabar 1994, 30).

The tolerant Arabian caliphs allowed pilgrims of other faiths access to Jerusalem. Not so the Egyptian Fatimid caliphs who gained control of the city in 969, destroying all the synagogues and churches. In 1071 the Seljuk Turks closed the pilgrimage routes, provoking the Crusades and resulting in the European seizure of Jerusalem in 1099. The Dome of the Rock was converted to Templum Domini, a Christian shrine. The Muslims recaptured the city in 1187, and Jerusalem remained under Islamic control until the nineteenth century.

Although the building has survived in much of its original form, changes have occurred over the centuries. Repairs were made under Caliph al-Mamun (reigned 813–833), and the dome was replaced in the twelfth century; before the successive restorations, its curve was probably slightly horseshoe shaped. More recently, its lead roof has been replaced with aluminum. The glass mosaics that covered the drum of the dome and the exterior walls above the sill line were replaced by ceramic tiles in 1554, when the lower windows were also replaced. In modern times, restorations were carried out in 1924 and 1959–1964. The most recent took place between 1992 and 1994; financed by the late King Hussein of Jordan, it included gilding the dome with 5,000 gold plates and cost U.S.$8 million.

See also

Masjed-e-Shah (Royal Mosque); Sultan Ahmet Mosque

Further reading

Bloom, Jonathan, ed. 2000. Early Islamic Art and Architecture. Burlington, VT: Ashgate.

Ettinghausen, Richard, and Oleg Grabar. 1994. The Art and Architecture of Islam, 650–1250. New Haven, CT: Yale University Press.

Frishman, Martin, and Hasan-Uddin Khan eds. 1994. Mosque: History, Architectural Development and Regional Diversity. New York: Thames and Hudson.

Dover Castle

Kent, England

The science of medieval warfare and the design of castle architecture developed side by side until the latter reached its highest degree of sophistication in the almost impregnable concentric castle, exemplified in the royal castle at Dover, known as the “key of England,” the first castle of its kind in western Europe. On a clear day the French coast, 21 miles (37 kilometers) across the English Channel, can be seen from the ramparts above the famous white cliffs of Dover, Europe’s historical gateway to Britain.

In 55 b.c. Julius Caesar landed his reconnaissance force nearby, and following a full-scale invasion in a.d. 43, the Romans built a walled town, Dubris (from which Dover is derived). They built an 80-foot-high (25-meter) flint pharos (lighthouse) on the nearby 375-foot (114-meter) Castle Hill, the site of an Iron Age earthworks that had existed long before. It was inevitable that the commanding position would continue to be used for defense. In the fifth century the Angles and Saxons came in the wake of the Roman withdrawal and founded a fortified town on the hill, employing the ancient defenses. Once Christianized, they built the church of St. Mary-in-Castro (St. Mary in the Fortress) as a chapel for the castle garrison and adapted the Roman lighthouse as part of its bell tower.

William I (the Conqueror) also recognized the strategic value of Dover. He instructed his half brother,