A tessera is an individual tile formed in the shape of a cube, used in creating a mosaic. It is known as an abaciscus or abaculus; the oldest known tesserae dates to the 3rd millennium BCE, discovered in the ancient city of Shahdad in Kerman province, Iran. In early antiquity, mosaics were formed from formed colored pebbles. By 200 BCE cut stone tesserae were being used in Hellenistic-Greek mosaics. For instance, a large body of surviving material from the Hellenistic period can be found in the mosaics of Delos, dating to the late 2nd century BCE. Ancient Roman decorative mosaic panels and floor mosaics were produced during the 2nd century BC at sites such as Pompeii. Marble or limestone were cut into small cubes and arranged into representational designs and geometric patterns. Tesserae were made from colored glass, or clear glass backed with metal foils; the Byzantines used tesserae with gold leaf, in which case the glass pieces were flatter, with two glass pieces sandwiching the gold. This produced a golden reflection emanating from in between the tesserae as well as their front, causing a far richer and more luminous effect than plain gold leaf would create.
Vitreous glass These are manufactured glass tiles made to size. They are made by molten glass being fired. An imprint of grooves is made on their underside for help with adhesion to cement. Ceramic tesserae These are the cheapest range of can be glazed or unglazed; the glazed ceramic tiles have the color painted onto the top of the clay and fired to a high temperature in a kiln. The unglazed or body glazed version has the color mixed into the wet clay so the color runs through them, they vary in size. Smalti This is the classic mosaic material, it is opaque glass fired in large slabs in a kiln and hand cut with a hammer and hardy chisel into small cubes. Their irregular finish makes them a wonderful reflector of light and this material is best used working straight into cement, it is sold by colour and weight. Gold smalti This tile is made with real gold and silver leaf sandwiched between two layers of glass and fired twice in the kiln to embed in the metal. Mirror Mirror adds great sparkle to a mosaic.
It is cheap as offcuts from a glass cutting shop are free. Use mirror glue. Stained glass Known for its translucent qualities stained glass is available in opaque form, it comes as large sheets. It can provide areas of larger tesserae pieces for contrast. Household ceramic tiles & china Colours and surfaces are limitless and can add texture and contrast to mosaic work in the technique known as trencadís or pique assiette. Tessellation — describes tessellation patterns Mosaic — describes techniques for assembling tesserae into a design
Siege of Thessalonica (1422–1430)
The siege of Thessalonica between 1422 and 1430 saw the Ottoman Empire under Sultan Murad II capture the city of Thessalonica. Thessalonica remained in Ottoman hands for the next five centuries, until it became part of the Kingdom of Greece in 1912. Thessalonica had been under Ottoman control from 1387 to 1403 before returning to Byzantine rule in the aftermath of the Battle of Ankara. In 1422, after the Byzantines supported Mustafa Çelebi as a rival pretender against him, Murad attacked Thessalonica. Unable to provide manpower or resources for the city's defense, its ruler, Andronikos Palaiologos, handed it over to the Republic of Venice in September 1423; the Venetians attempted to persuade the Sultan to recognize their possession, but failed as Murad considered the city his by right and the Venetians to be interlopers. This impasse led to an Ottoman blockade of Thessalonica, which flared up with direct attacks on the city. At the same time, the conflict was fought as a series of raids by both sides against the other's territories in the Balkans and the Aegean islands.
The Venetians tried to apply pressure by blocking the passage of the Dardanelles at Gallipoli, with little success. The blockade reduced the inhabitants to near starvation, led many to flee the city; the restrictions placed on them by the siege, the inability of Venice to properly supply and guard the city, the violations of their customary rights, rampant profiteering by Venetian officials led to the formation of a pro-surrender party within the city, which gained strength among the inhabitants. The city's metropolitan bishop, encouraged his flock to resist. However, by 1426, with Venice's inability to secure peace on its own terms evident, a majority of the local population had come to prefer a surrender to avoid the pillage that would accompany a forcible conquest. Venice's efforts to find allies against the Ottomans failed: the other regional potentates either pursued their own course, were themselves antagonistic to the Venetians, or were defeated by the Ottomans. After years of inconclusive exchanges, the two sides prepared for a final confrontation in 1429.
In March, Venice formally declared war on the Ottomans, but then the conservative mercantile aristocracy running the Republic were uninterested in raising an army sufficient to protect Thessalonica, let alone to force the Sultan to seek terms. In early 1430, Murad was able to concentrate his forces against Thessalonica, taking it by storm on 29 March 1430; the privations of the siege and the subsequent sack reduced the city to a shadow of its former self, from as many as 40,000 inhabitants to c. 2,000, necessitated large-scale resettlement in the following years. Venice concluded a peace treaty with the Sultan in July. Over the next few decades, the antagonism between Venice and the Ottomans morphed into a rivalry over control of Albania. In the 14th century, the nascent Ottoman Empire were a rising power in the Near East. After subduing much of Anatolia, with the capture of Gallipoli in 1354, Ottoman Turks acquired a foothold in the Balkans; the Christian powers of the region, notably the declining Byzantine Empire, were weak and divided, allowing a rapid Turkish expansion across the region, conducted both by the Ottomans themselves and by semi-independent Turkish ghazi warrior-bands.
In 1369 the Ottomans were able to capture Adrianople, the third-most important city of the Byzantine Empire after its capital Constantinople and Thessalonica. Thessalonica, ruled by the Byzantine prince and future emperor Manuel II Palaiologos, itself surrendered in 1387 after a lengthy siege, along with the cities of Christopolis and Chrysopolis; the surrendered cities were allowed complete autonomy in exchange for payment of the haraç poll-tax. Following the death of Emperor John V Palaiologos in 1391, Manuel II escaped Ottoman custody and went to Constantinople, where he was crowned emperor, succeeding his father; this angered Sultan Bayezid I, who laid waste to the remaining Byzantine territories, turned on Chrysopolis, captured by storm and destroyed. Thessalonica submitted again to Ottoman rule at this time after a brief period of resistance, but was treated more leniently: although the city was brought under full Ottoman control, the Christian population and the Church retained most of their possessions, the city retained its institutions.
Thessalonica remained in Ottoman hands until 1403, when Emperor Manuel II sided with Bayezid's eldest son Süleyman in the Ottoman succession struggle that broke out following the crushing defeat of the Ottomans and the capture of Bayezid at the Battle of Ankara against the Turco-Mongol conqueror Timur in 1402. In exchange for his support by the Treaty of Gallipoli, the Byzantine emperor secured the return of Thessalonica, part of its hinterland, the Chalcidice peninsula, the coastal region between the rivers Strymon and Pineios. Despite the restoration of Byzantine rule, relations between Thessalonica and Constantinople remained troubled, with Thessalonica's local aristocracy jealously guarding their extensive privileges, which according to modern scholars amounted to virtual autonomy; this was part of a wider phenomenon attested for several cities during the last century of Byzantine history, as central authority weakened and centrifugal tendencies manifested themselves. In Thessalonica's case, a tendency to pursue increased independence from the imperial capital had been evident at least since the Zealot movement of the mid-14th century, had been reinforced by Manuel II's autonomous regime in 1382–1387.
Thus, after they returned to Byzantine control Thessalonica and the surrounding region were given as an autonomous appanage
Paleochristian and Byzantine monuments of Thessaloniki
The city of Thessaloniki in Macedonia, for several centuries the second-most important city of the Byzantine Empire, played an important role for Christianity during the Middle Ages and was decorated by impressive buildings. In 1988, fifteen monuments of Thessaloniki were listed as UNESCO World Heritage Sites: City Walls Rotunda of Saint George Church of Acheiropoietos Church of St. Demetrios Latomou Monastery Church of St. Sophia Church of Panagia Chalkeon Church of St. Panteleimon Church of the Holy Apostles Church of St. Nicholas Orphanos Church of St. Catherine Church of Christ Saviour Blatades Monastery Church of Prophet Elijah Byzantine Bath Παλαιοχριστιανικά και βυζαντινά μνημεία Θεσσαλονίκης. ODYSSEUS Portal. Hellenic Ministry of Culture. Retrieved 24 July 2012
Church of Panagia Chalkeon
The Church of Panagia Chalkeon is an 11th-century Byzantine church in the northern Greek city of Thessaloniki. The church is located at Dikastirion Square, north of the Via Egnatia at the point where it crosses the Aristotelous Avenue, which leads to the Aristotelous Square; the archaeological site of the city's Roman forum is located northeast, while its name, which translates as "the Virgin of the Copper-smiths", derives from its proximity to the area traditionally occupied by the city's coppersmiths. According to the founder's inscription above the west entrance, the church was built in 1028 by the protospatharios Christopher, katepano of Longobardia, his wife and two daughters; the inscription reads: This once profane place is dedicated as an eminent church to the Mother of God by Christopher, the most illustrious royal protospatharios and governor of Lagouvardia, his wife Maria, their children Nicephorus and Catacale, in the month of September, indiction XII, in the year 6537. Christopher's tomb was located in an arcosolium on the church's northern wall.
The ground plan is that of a classic "cross-in-square-form" typical of Macedonian-period architecture, with four columns and three domes, one central and two over the narthex. The entire building is built of bricks, which gave it the popular nickname "Red Church"; the exterior is enlivened with a variety of arches and pilasters, elements which can be traced to Constantinopolitan influence. The use of arches with several setbacks gives the building a "sculpted" appearance. A marble cornice runs around the whole church, giving the building distinctive upper and lower sections; the lower section is more spare, while the upper section is decoratively distinguished by half-columns between arches, saw-tooth courses where the wall meets the roof. The interior of the church is divided into three sections: The narthex, the naos, the sanctuary; the narthex is covered by three barrel vaults and has an upper gallery, used as a sacristy. There was never, however, a stair leading up to it. Anna Tsitouridou speculates that it may have been accessed by a ladder through a now closed up arched window on the northwest corner of the church.
In the naos, four light grey marble columns form a square and support the arches of the four barrel-vaults that make up the arms of the cross going out. In the center of the square is the dome. Pendentives between the arches create a circular base for the dome above; the dome is 3.8m wide and its height is 5.3m. It is octagonal, containing sixteen windows in one atop the other; the arms of the cross can be seen on the exterior, with saddle back roofs over their great barrel vaults, triangular pediments emphasising their ends. Domical vaults cover the four bays between the arms of the cross. Though founders' tombs are placed in the narthex of their churches, at Panagia Chalkeon the tomb believed to be Christopher the founder’s is found in a niche in the north wall of the naos; the sanctuary is divided into three sections: The central main body of the sanctuary, the prothesis, the diaconicon. The central section of the sanctuary has a wide apse, “semicircular within, three-sided without.” The other two bays have apses “semicircular inside and out.”
The church has some anomalies. There is sculptural decoration on the capitals of the four columns in the naos, the doorframes of the narthex; the column capitals are decorated with reliefs of laurel leaves and knot patterns which contain crosses and rosettes in them. The lintel of the royal door leading from the narthex into the naos is decorated with a twisting band design, forming squares and circles in relief; the circles contain rosettes and it is discernible that crosses used to be in the squares, but have been scraped off. The walls were covered with paintings, but the majority of the paintings have fallen down, few of the remaining paintings are in good condition; the paintings are from the time the church was built, except a few from the 14th century whose remnants can be viewed on the west wall. According to Sharon Gerstel, “The church of Panagia ton Chalkeon... preserves one of the earliest multi-register sanctuary programs in Macedonia.”In the conch of the apse stands the Virgin Orant flanked by two archangels.
Two registers below, in the bottom register of the sanctuary, are four half-length depictions of "anargyroi," or “unmercenaries”: healers who refused payment for their healing services. According to Gerstel, the presence of non-episcopal figures in the bema dates the iconographical program to "a period when a wider variety of saints could be located in the sanctuary.”Inscribed on the eastern arch of the church are these words: “Beholding the altar of the Lord, Stand trembling, O man! For within, Christ is sacrificed daily, and the powers of incorporeal angels, Circle around in fear.”This message borders a depiction of the apostles taking the last supper, the earliest extant representation of the scene in the bema of a Byzantine church. In this version of the last supper, the offering of the bread is painted on the south wall of the bema, the offering of the wine on the north wall opposite; this in effect, according to Gerstel, engulfs the altar and the celebrant and equates “the priest with Christ as the giver of the sacrifice.”In the main dome there is a
Arch of Galerius and Rotunda
The Arch of Galerius or Kamara and the Rotunda are neighbouring early 4th-century AD monuments in the city of Thessaloniki, in the region of Central Macedonia in northern Greece. The 4th-century Roman Emperor Galerius commissioned these two structures as elements of an imperial precinct linked to his Thessaloniki palace. Archeologists have found substantial remains of the palace to the southwest; these three monumental structures were connected by a road that ran through the arch, which rose above the major east-west road of the city. At the crux of the major axes of the city, the Arch of Galerius emphasized the power of the emperor and linked the monumental structures with the fabric of 4th-century Thessaloniki; the arch was composed of a masonry core faced with marble sculptural panels celebrating a victory over the Sassanid Persians. About two-thirds the arch is preserved; the Rotunda was a massive circular structure with a masonry core that had an oculus like the Pantheon in Rome. It has gone through multiple periods of use and modification as a polytheist temple, a Christian basilica, a Muslim mosque, again a Christian church.
A minaret is preserved from its use as a mosque, ancient remains are exposed on its southern side. The Arch of Galerius stands on what is now the intersection of Dimitriou Gounari streets; the arch was built in 298 to 299 AD and dedicated in 303 AD to celebrate the victory of the tetrarch Galerius over the Sassanid Persians at the Battle of Satala and capture of their capital Ctesiphon in 298. The structure was an octopylon forming a triple arch, built of a rubble masonry core faced first with brick and with marble panels with sculptural relief; the central arched opening was 9.7 m wide and 12.5 m high, the secondary openings on other side were 4.8 m wide and 6.5 m high. The central arch spanned the portion of the Via Egnatia. A road connecting the Rotunda with the Palace complex passed through the arch along its long axis. Only the northwestern three of the eight pillars and parts of the masonry cores of the arches above survive: i.e. the entire eastern side and the southernmost one of the western pillars are lost.
Extensive consolidation with modern brick has been performed on the exposed masonry cores to protect the monument. The two pillars flanking the central arched passageway retain their sculpted marble slabs, which depict the wars of Galerius against the Persians in broadly panegyric terms. Understanding of the sculptural program of the arch is limited by the loss of the majority of the marble panels, but the remains give an impression of the whole. Four vertically stacked registers of sculpted decoration were carved on each pillar, each separated by elaborate moldings. A label for the Tigris River indicates that there were labels on other representations as the builders deemed necessary. Artistic license was taken in the representations, for instance, the Caesar Galerius is shown in personal combat with the Sassanid Shah Narses in one of the panels. On the arch a mounted Galerius attacks a mounted Narses with a lance as an eagle bearing a victory wreath in its talons approaches Galerius; the Caesar sits securely on his rearing horse.
Terrified Persians cower under the hooves of the Caesar's horse in the chaos of battle. The panel expresses the power of the Caesar Galerius; the relief of the imperial family conjoined in a sacrifice of thanksgiving owes its distant prototype to the Augustan reliefs on the Ara Pacis in Rome. Galerius' wife, Diocletian's daughter Valeria, is shown at his side, helping authenticate his connection to his predecessor. Here as elsewhere all the faces have been chiselled off, whether as damnatio memoriae or in cultural intolerance of images. In another panel, the tetrarchs are all arrayed in the toga as a Victoria holds a victory wreath out to the heads of the two Augusti. A third panel celebrates the unity of the tetrarchy, with a depiction of the tetrarchs standing together. Only Galerius is dressed in armor, he makes the offering upon the altar. What remains of the arch asserts the glory of the tetrarchy and the prominence of Galerius within that system; the arch celebrates the Roman Empire as part of Galerius’ victory over the Sassanid king.
Galerius is pictured on his horse at the right, while attacking a Sassanid guard. The Rotunda of Galerius is 125m northeast of the Arch of Galerius at 40°37'59.77"N, 22°57'9.77"E. It is known as the Greek Orthodox Church of Agios Georgios, is informally called the Church of the Rotunda; the cylindrical structure was built in 306 AD on the orders of the tetrarch Galerius, thought to have intended it to be his mausoleum. It was more intended as a temple; the Rotunda has a diameter of 24.5 m. Its walls are more than 6 m thick, why it has withstood Thessaloniki's earthquakes; the walls are interrupted with the west bay forming the entrance. A flat brick dome, 30 m high at the peak, crowns the cylindrical structure. In its original design, the dome of the Rotunda had an oculus. After Galerius's death in 311, he was buried at Gamzigrad near Serbia; the Rotunda stood em
The Byzantine Empire referred to as the Eastern Roman Empire or Byzantium, was the continuation of the Roman Empire in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinople. It survived the fragmentation and fall of the Western Roman Empire in the 5th century AD and continued to exist for an additional thousand years until it fell to the Ottoman Turks in 1453. During most of its existence, the empire was the most powerful economic and military force in Europe. Both the terms "Byzantine Empire" and "Eastern Roman Empire" are historiographical terms created after the end of the realm. Several signal events from the 4th to 6th centuries mark the period of transition during which the Roman Empire's Greek East and Latin West diverged. Constantine I reorganised the empire, made Constantinople the new capital, legalised Christianity. Under Theodosius I, Christianity became the Empire's official state religion and other religious practices were proscribed.
Under the reign of Heraclius, the Empire's military and administration were restructured and adopted Greek for official use in place of Latin. Thus, although the Roman state continued and its traditions were maintained, modern historians distinguish Byzantium from ancient Rome insofar as it was centred on Constantinople, oriented towards Greek rather than Latin culture, characterised by Eastern Orthodox Christianity; the borders of the empire evolved over its existence, as it went through several cycles of decline and recovery. During the reign of Justinian I, the empire reached its greatest extent after reconquering much of the Roman western Mediterranean coast, including North Africa and Rome itself, which it held for two more centuries; the Byzantine–Sasanian War of 602–628 exhausted the empire's resources and contributed to major territorial losses during the Early Muslim conquests of the 7th century, when it lost its richest provinces and Syria, to the Arab caliphate. During the Macedonian dynasty, the empire expanded again and experienced the two-century long Macedonian Renaissance, which came to an end with the loss of much of Asia Minor to the Seljuk Turks after the Battle of Manzikert in 1071.
This battle opened the way for the Turks to settle in Anatolia. The empire recovered during the Komnenian restoration, by the 12th century Constantinople was the largest and wealthiest European city. However, it was delivered a mortal blow during the Fourth Crusade, when Constantinople was sacked in 1204 and the territories that the empire governed were divided into competing Byzantine Greek and Latin realms. Despite the eventual recovery of Constantinople in 1261, the Byzantine Empire remained only one of several small rival states in the area for the final two centuries of its existence, its remaining territories were progressively annexed by the Ottomans over the 15th century. The Fall of Constantinople to the Ottoman Empire in 1453 ended the Byzantine Empire; the last of the imperial Byzantine successor states, the Empire of Trebizond, would be conquered by the Ottomans eight years in the 1461 Siege of Trebizond. The first use of the term "Byzantine" to label the years of the Roman Empire was in 1557, when the German historian Hieronymus Wolf published his work Corpus Historiæ Byzantinæ, a collection of historical sources.
The term comes from "Byzantium", the name of the city of Constantinople before it became Constantine's capital. This older name of the city would be used from this point onward except in historical or poetic contexts; the publication in 1648 of the Byzantine du Louvre, in 1680 of Du Cange's Historia Byzantina further popularised the use of "Byzantine" among French authors, such as Montesquieu. However, it was not until the mid-19th century that the term came into general use in the Western world; the Byzantine Empire was known to its inhabitants as the "Roman Empire", the "Empire of the Romans", "Romania", the "Roman Republic", as "Rhōmais". The inhabitants called themselves Romaioi and as late as the 19th century Greeks referred to Modern Greek as Romaiika "Romaic." After 1204 when the Byzantine Empire was confined to its purely Greek provinces the term'Hellenes' was used instead. While the Byzantine Empire had a multi-ethnic character during most of its history and preserved Romano-Hellenistic traditions, it became identified by its western and northern contemporaries with its predominant Greek element.
The occasional use of the term "Empire of the Greeks" in the West to refer to the Eastern Roman Empire and of the Byzantine Emperor as Imperator Graecorum were used to separate it from the prestige of the Roman Empire within the new kingdoms of the West. No such distinction existed in the Islamic and Slavic worlds, where the Empire was more straightforwardly seen as the continuation of the Roman Empire. In the Islamic world, the Roman Empire was known as Rûm; the name millet-i Rûm, or "Roman nation," was used by the Ottomans through the 20th century to refer to the former subjects of the Byzantine Empire
History of Roman and Byzantine domes
The History of Roman and Byzantine domes traces the architecture of domes throughout the ancient Roman Empire and its medieval continuation, today called the Byzantine Empire. Domes were important architectural elements in both periods and had widespread influence on contemporary and styles, from Russian and Ottoman architecture to the Italian Renaissance and modern revivals; the domes were customarily hemispherical, although octagonal and segmented shapes are known, they developed in form and structure over the centuries. Early examples rested directly on the rotunda walls of round rooms and featured a central oculus for ventilation and light. Pendentives became common in the Byzantine period, provided support for domes over square spaces. Early wooden domes are known only from a literary source, but the use of wooden formwork and unskilled labor enabled domes of monumental size in the late Republic and early Imperial period, such as the so-called "Temple of Mercury" bath hall at Baiae. Nero introduced the dome into Roman palace architecture in the 1st century and such rooms served as state banqueting halls, audience rooms, or throne rooms.
The Pantheon's dome, the largest and most famous example, was built of concrete in the 2nd century and may have served as an audience hall for Hadrian. Imperial mausolea, such as the Mausoleum of Diocletian, were domed beginning in the 3rd century; some smaller domes were built with a technique of using ceramic tubes in place of a wooden centering for concrete, or as a permanent structure embedded in the concrete, but light brick became the preferred building material over the course of the 4th and 5th centuries. Brick ribs allowed for a thinner structure and facilitated the use of windows in the supporting walls, replacing the need for an oculus as a light source. Christian baptisteries and shrines were domed in the 4th century, such as the Lateran Baptistery and the wooden dome over the Church of the Holy Sepulchre. Constantine's octagonal palace church in Antioch may have been the precedent for similar buildings for centuries afterward; the first domed basilica may have been built in the 5th century, with a church in southern Turkey being the earliest proposed example, but the 6th century architecture of Justinian made domed church architecture standard throughout the Roman east.
His Hagia Sophia and Church of the Holy Apostles inspired copies in centuries. Cruciform churches with domes at their crossings, such as the churches of Hagia Sophia in Thessaloniki and St. Nicholas at Myra, were typical of 7th and 8th century architecture and bracing a dome with barrel vaults on four sides became the standard structural system. Domes over windowed drums of cylindrical or polygonal shape were standard after the 9th century. In the empire's period, smaller churches were built with smaller diameter domes less than 6 meters after the 10th century. Exceptions include the 11th century domed-octagons of Hosios Loukas and Nea Moni, the 12th century Chora Church, among others; the cross-in-square plan, with a single dome at the crossing or five domes in a quincunx pattern, as at the Church of St. Panteleimon, was the most popular type from the 10th century until the fall of Constantinople in 1453. Rounded arches and domes distinguish Roman architecture from that of Ancient Greece and were facilitated by the use of concrete and brick.
By varying the weight of the aggregate material in the concrete, the weight of the concrete could be altered, allowing lighter layers to be laid at the top of concrete domes. But concrete domes required expensive wooden formwork called shuttering, to be built and kept in place during the curing process, which would have to be destroyed to be removed. Formwork for brick domes need not be kept in place as long and could be more reused. Roman domes were used in baths, villas and tombs. Oculi were common features, they were customarily hemispherical in shape and or concealed on the exterior. In order to buttress the horizontal thrusts of a large hemispherical masonry dome, the supporting walls were built up beyond the base to at least the haunches of the dome and the dome was also sometimes covered with a conical or polygonal roof. A variety of other shapes, including shallow saucer domes, segmental domes, ribbed domes were sometimes used; the audience halls of many imperial palaces were domed. Domes were very common over polygonal garden pavilions.
Construction and development of domes declined in the west with the decline and fall of the western portion of the empire. The term "Byzantine", invented in 1557 by historian Hieronymus Wolf, became popular in the 19th century and is used to refer to the medieval eastern Roman Empire with its capital at Constantinople, the former town of Byzantion. In the Byzantine period, a supporting structure of four arches with pendentives between them allowed the spaces below domes to be opened up. Pendentives allowed for weight loads to be concentrated at just four points on a more practical square plan, rather than a circle. Domes were important elements of baptisteries and tombs, they were hemispherical and had, with occasional exceptions, windowed drums. Roofing for domes ranged from simple ceramic tile to more expensive, more durable, more form-fitting lead sheeting; the domes and drums incorporated wooden tension rings at several levels to resist deformation in the mortar and allow for faster construction.
Metal clamps between stone cornice blocks, metal tie rods, metal chains were used to stabilize domed buildings. Timber belts at the bases of domes helped to stabilize the walls below them during earthquakes, but the domes themselves remained vulnerable to collapse; the surviving ribbed or pumpkin dome exa