History of Roman and Byzantine domes

[42] Because there is no indication that mosaic or other facing material had ever been applied to the surface of the dome, it may have been hidden behind a tent-like fabric canopy like the pavilion tents of Hellenistic (and earlier Persian) rulers.

[46] The expensive and lavish decoration of the palace caused such scandal that it was abandoned soon after Nero's death and public buildings such as the Baths of Titus and the Colosseum were built at the site.

The building's dimensions seem to reference Archimedes' treatise On the Sphere and Cylinder, the dome may use rows of 28 coffers because 28 was considered by the Pythagoreans to be a perfect number, and the design balances its complexity with underlying geometrical simplicity.

[67] In the middle of the 2nd century, some of the largest domes were built near present-day Naples, as part of large bath complexes taking advantage of the volcanic hot springs in the area.

The dome of the "Temple of Diana", which may have been a nymphaeum as part of the bath complex, can be seen to have had an ogival section made of horizontal layers of mortared brick and capped with light tufa.

[70] Although rarely used, the pendentive dome was known in 2nd century Roman architecture and possibly earlier, in funerary monuments such as the Sedia dei Diavolo [it] and the Torracio della Secchina [it] on the Via Nomentana.

[15] A stone corbelled dome 5.806 meters (19.05 ft) wide, later known as "Arthur's O'on", was located in Scotland three kilometers north of the Falkirk fort on the Antonine Wall and may have been a Roman victory monument from the reign of Carausius.

[98] The Church of the Holy Apostles, or Apostoleion, probably planned by Constantine but built by his successor Constantius in the new capital city of Constantinople, combined the congregational basilica with the centralized shrine.

[108] The oblong decagon of today's St. Gereon's Basilica in Cologne, Germany, was built upon an extraordinary and richly decorated 4th century Roman building with an apse, semi-domed niches, and dome.

[111] The largest centrally planned Early Christian church, Milan's San Lorenzo Maggiore, was built in the middle of the 4th century while that city served as the capital of the Western Empire and may have been domed with a light material, such as timber or cane.

[115] The building may have been the church of the nearby imperial palace and a proposed construction between 355 and 374 under the Arian bishop Auxentius of Milan, who later "suffered a kind of damnatio memoriae at the hands of his orthodox successors", may explain the lack of records about it.

[119] The early church of St. John at Ephesus mentioned in a late fourth century account by Etheria appears to have been a timber-roofed cruciform building with arms of roughly equal length and four central piers supporting a dome approximately 3.5 meters wide.

[129] The square bay with an overhead sail vault or dome on pendentives became the basic unit of architecture in the early Byzantine centuries, found in a variety of combinations.

[144] Under Justin I in the 520s, Justinian seems to have razed the Basilica of St. John in Ephesus and replaced it with a greek cross cruciform building with five domes similar to his later Church of the Holy Apostles in Constantinople.

[157] One theory is that the original dome continued the curve of the existing pendentives (which were partially reconstructed after its collapse), creating a massive sail vault pierced with a ring of windows.

[158][159] This vault would have been part of a theoretical sphere 46 meters (151 ft) in diameter (the distance of the diagonal of the square bay defined by the pendentives), 7 percent greater than the span of the Pantheon's dome.

[166] Iron cramps between the marble blocks of its cornice helped to reduce outward thrusts at the base and limit cracking, like the wooden tension rings used in other Byzantine brick domes.

[175] The second most important church in the city after the Hagia Sophia, it fell into disrepair after the Latin occupation of Constantinople between 1204 and 1261 and it was razed to the ground by Mehmed the Conqueror in 1461 to build his Fatih Mosque on the site.

The example at Qasr ibn Wardan (564) in the desert of eastern Syria is particularly impressive, containing a governor's palace, barracks, and a church built with techniques and to plans possibly imported from Constantinople.

It was connected to the imperial living quarters and was a space used for assembly before religious festivals, high promotions and consultations, as a banqueting hall, a chapel for the emperor, and a throne room.

The earliest cross-in-square in Greece is the Panagia church at the monastery of Hosios Loukas, dated to the late 10th century, but variations of the type can be found from southern Italy to Russia and Anatolia.

[206] The katholikon of Nea Moni, a monastery on the island of Chios, was built some time between 1042 and 1055 and featured a nine sided, ribbed dome rising 15.62 meters (51.2 ft) above the floor (this collapsed in 1881 and was replaced with the slightly taller present version).

[211] Called the "Mouchroutas Hall", it may have been built as part of an easing in tensions between the court of Manuel I Komnenos and Kilij Arslan II of the Sultanate of Rum around 1161, evidence of the complex nature of the relations between the two states.

The account, written by Nicholas Mesarites shortly before the Fourth Crusade, is part of a description of the coup attempt by John Komnenos in 1200, and may have been mentioned as a rhetorical device to disparage him.

It is characterized by a polygonal drum with rounded colonnettes at the corners, all brick construction, and faces featuring three arches stepped back within one another around a narrow "single-light window".

Georgia and Armenia produced many central planned, domed buildings in the 7th century and, after a lull during the Arab invasions, the architecture flourished again in the Middle Byzantine Period.

Churches with stone domes became the standard type after the 7th century, perhaps benefiting from a possible exodus of stonecutters from Syria, but the long traditions of wooden construction carried over stylistically.

[232] Bulbous onion domes on tall drums were a development of northern Russia, perhaps due to the demands of heavy ice and snowfall along with the more rapid innovation permitted by the Novgorod region's emphasis on wooden architecture.

St. Mark's Basilica was modeled on the now-lost Byzantine Church of the Holy Apostles in Constantinople, and Périgueux Cathedral in Aquitaine (c. 1120) likewise has five domes on pendentives in a Greek cross arrangement.

[244] The technique of using wooden tension rings at several levels within domes and drums to resist deformation, frequently said to be a later invention of Filippo Brunelleschi, was common practice in Byzantine architecture.