Byzantium and the Early Church

In the fourth century the Roman empire became Christian, and the new religion needed buildings of a kind antiquity had never made. A pagan temple housed a statue and was entered by priests; worship happened at the altar outside. A church had to hold the whole community indoors, facing an altar, for a liturgy of readings, processions and communion, and it had to provide separately for baptism and for the veneration of martyrs. Over the next thousand years the builders of Rome, Ravenna and Constantinople, and after them those of the Balkans and of Russia, answered with two great spatial ideas, the long hall and the domed centre, and with endless combinations of the two.

The basilica church

After the Edict of Milan in 313, Constantine built churches in Rome, Constantinople and the Holy Land on an imperial scale. The model he chose was not the temple but the basilica, the great covered hall that stood beside every Roman forum, used for trade and the law courts. It was the right size and the right shape: a long central nave flanked by lower aisles, lit by a clerestory, with an apse at one end where a magistrate had once sat and where now the bishop sat behind the altar. Vitruvius had already given its proportions.

℟The forum basilica

Make a basilica between a third and a half as broad as it is long; make each aisle a third of the width of the central space, and the columns as high as the aisles are broad.

W = ⅓ to ½ L; aisle = ⅓ nave; column height = aisle width; upper columns ¼ smaller

The Christian basilica was organised as a path. From the street one entered a colonnaded forecourt, the atrium, with a fountain for washing, then a porch across the front, the narthex, then the nave, whose colonnades led the eye and the procession toward the altar before the apse. A great arch, later called the triumphal arch, framed the apse; in the largest churches, such as Old St Peter’s (begun in the 320s), a transept crossed the building before it and there were two aisles on each side.

℟From the atrium to the apse

Order the church as a single path: a colonnaded atrium, a narthex, the long nave drawn toward the altar, and the apse framed by a triumphal arch at the end of the axis.

The structure was simple and fast to build. Brick-faced concrete walls stood on colonnades, often of columns and capitals taken from older buildings (spolia); the nave was roofed not with a vault but with timber trusses, whose tie-beams contain their own thrust, so that walls on slender columns could span twenty metres and more. Santa Sabina in Rome (422–432), with its two rows of twelve fluted Corinthian columns carrying arches, remains the clearest surviving example.

The exteriors were plain brick; the interiors were meant to dazzle. Marble revetment covered the lower walls, gilded coffered ceilings or painted trusses the roof, and mosaics of glass and gold filled the apse and the walls above the colonnades, as they still do at Santa Maria Maggiore in Rome and at Sant’Apollinare Nuovo and Sant’Apollinare in Classe in Ravenna. The church was an image of heaven entered from the ordinary street.

The centralised building

Beside the basilica stood a second kind of building, round or polygonal, descended from Roman mausolea and bath halls. It was used for the baptistery, where the community gathered round the font, and for the martyrium, built over a martyr’s grave or a holy place. Santa Costanza in Rome (c. 350), built as the mausoleum of Constantine’s daughter, has a central dome on a ring of paired columns within a barrel-vaulted ambulatory; the Anastasis rotunda over the tomb of Christ in Jerusalem was the most famous of all. A centralised plan puts everything under one point: the dome.

Justinian and the dome

In the eastern empire the tradition of vaulting in brick was strong, and in the sixth century its builders brought the dome from the tomb and the baptistery into the main church. Under Justinian (527–565) two churches of the new kind were begun within a few years: Sts Sergius and Bacchus in Constantinople (c. 527–536) and San Vitale in Ravenna (consecrated 547), both domed octagons surrounded by ambulatories and galleries. The problem that faced their builders, and every builder of a dome over anything but a round room, was how to set the circle of a dome on the corners of a square or polygon.

The answer that made Byzantine architecture was the pendentive. A sphere passing through the four corners of a square bay is cut by the four sides into four arches, and by the horizontal plane through their crowns into a circle; the curved triangles left in the corners carry that circle down to the four piers. The older alternative was the squinch, an arch or niche across each corner that turns the square into an octagon; it was used in Persia and the Caucasus and appears in Byzantine churches of the eleventh century.

Hagia Sophia

In January 532 the Nika riot burned the cathedral of Constantinople. Within weeks Justinian had commissioned a replacement from two men known as theorists rather than builders: Anthemius of Tralles, a mathematician who wrote on burning mirrors, and Isidore of Miletus, a geometer. Their church of Holy Wisdom, Hagia Sophia, was dedicated five years later, in December 537. It remained the largest church in Christendom for almost a thousand years.

The building fuses the basilica and the dome. At its centre four great piers and four arches define a square about 31 m across; pendentives carry a dome whose crown is now some 55.6 m above the floor. To east and west two of the great arches open into semidomes of the same radius, and each semidome opens in turn into two smaller exedrae with conches and an axial bay, so that the nave is extended to some 70 m by a cascade of curved shells. North and south, the arches are closed by thin window-pierced walls over two storeys of colonnades, beyond which run aisles and galleries. Enormous buttress piers outside take the thrust of the dome across the aisles.

At the base of the dome forty windows alternate with forty ribs. Procopius, the historian of Justinian’s buildings, wrote that the dome seemed to hang from heaven on a golden chain, and the effect has struck visitors ever since. Inside, walls of coloured marble and a vault of gold mosaic made the building, in the eyes of the envoys of Prince Vladimir of Kyiv four centuries later, a place where they did not know whether they were in heaven or on earth.

The boldness had a price. The first dome, which was very shallow, fell in 558 after earthquakes had already disturbed its supports. Isidore the Younger rebuilt it about 6 m higher, reducing its outward thrust, and the new dome was dedicated in 562. Parts of it collapsed and were rebuilt after earthquakes in 989 and 1346, and buttresses were added round the building over the centuries. After the Ottoman conquest of 1453 it became a mosque; its architects, above all Sinan, took it as the starting point for the great domed mosques of Istanbul and Edirne.

℟Make a shallow dome steeper

A shallow dome pushes harder outward than a steep one of the same span: when the first dome of Hagia Sophia fell, it was rebuilt with a higher rise so that its thrust would be more nearly vertical.

rise raised by ≈ 6 m (about 20 Byzantine feet), 558–562

Building in brick

Byzantine masonry is distinctive. Walls were built of thin, square bricks laid in beds of mortar almost as thick as the bricks themselves, often in bands with courses of dressed stone. Vaults and domes were raised with little or no centring: bricks were laid in rings, each ring holding itself as it closed, or in courses leaning against a wall so that each could be set without support. The mortar, slow to set, allowed a building to settle, which is why Hagia Sophia’s piers leaned and why its builders had to learn from its movements. In the middle Byzantine period exteriors became decorative, with bands of brick and stone framing each block (cloisonné masonry) and patterns laid in the brickwork.

The cross-in-square

After the long crisis of Iconoclasm (726–843), which banned religious images, the typical Byzantine church became small, centralised and richly decorated. Its plan, the cross-in-square, divides a square into nine bays. The central bay is covered by a dome on pendentives, usually raised on a windowed drum and carried on four columns; the four bays around it form the arms of a cross, covered by barrel vaults; the four corner bays are lower. Three apses project to the east, and a narthex runs across the west. The interior reads as a cross inscribed in a square; the exterior as a pyramid of volumes rising to the dome.

The church of Constantine Lips in Constantinople (907), the Theotokos church at Hosios Loukas in Greece (tenth century) and the Myrelaion show the type in its classic form. Other plans flourished alongside it, notably the octagonal naos with its dome on squinches, as in the katholikon of Hosios Loukas and at Nea Moni on Chios. The richest churches carried five domes, over the centre and the corners or over the arms of a Greek cross: Justinian’s Holy Apostles in Constantinople, now lost, was copied at San Marco in Venice (1063–1094).

℟Five domes in a quincunx

Crown the four corner bays of a cross-in-square with smaller domes on drums around the great central dome, making a five-domed quincunx.

Inside, the decoration followed a fixed scheme: Christ Pantokrator in the dome, the Virgin in the apse, the feasts of the church year in the vaults, saints on the walls. A low marble screen, the templon, divided the sanctuary from the nave; hung with icons, it grew in later centuries into the iconostasis, the solid wall of images that still dominates Orthodox interiors. Late Byzantine art reached its last flowering in the mosaics and frescoes of the Chora church in Constantinople (1315–1321).

Russia

In 988 Prince Vladimir of Kyiv accepted baptism from Byzantium, and Greek masters came north to build. The cathedral of St Sophia in Kyiv, begun in the 1030s, is a cross-in-square multiplied, with five aisles, galleries and thirteen domes; St Sophia in Novgorod (1045–1050) adapted the type to a harsher climate with massive walls and small windows. In twelfth-century Vladimir-Suzdal, churches of white limestone such as the Intercession on the Nerl (1165) combined the cross-in-square with pilaster strips, carved blind arcades and walls ending in semicircular gables (zakomary) that follow the vaults inside.

℟Let the roofline follow the vaults

Divide each wall into bays with pilaster strips and end each bay in a semicircular gable, the zakomara, that follows the curve of the barrel vault behind it; shape the roof to the gables.

usually 3 zakomary per façade, one per bay

When Moscow became the centre of a unified Russian state, Ivan III brought the Bolognese engineer Aristotele Fioravanti to rebuild the Dormition Cathedral in the Kremlin (1475–1479). Its five domes over a hall of equal bays became the model for the cathedrals of Muscovy. The Russian church was vertical from the start, its domes lifted high on drums so that they could be seen above the roofs and the forest; in the sixteenth and seventeenth centuries the domes swelled into the bulbous onion dome, usually an outer shell of timber sheathed in gilded or painted metal over a lower masonry vault.

℟The onion dome on a tall drum

Lift each dome on a tall drum and give it a bulbous outer shell that swells beyond the drum and draws up to a point under the cross; build the shell as a light timber frame sheathed in metal over the structural vault below.

onion Ø ≈ 1.2–1.3 × drum Ø; height ≈ 2 × its base radius

Two native inventions completed the Russian church. The first was the tented church, in which a tall octagonal pyramid of brick, the shatyor, replaced the dome; it was probably a translation of timber church towers into masonry. The Church of the Ascension at Kolomenskoye (1532) is the first great example; St Basil’s on Red Square (1555–1561) gathers a tent and eight domed chapels into a single fantastic silhouette. The second was the kokoshnik, a pointed decorative gable set in tiers round the base of a drum or tent, which in seventeenth-century Moscow churches such as the Trinity in Nikitniki turned the roof into a cascade of arches, carved brick and coloured tiles.

In the 1650s the Church authorities discouraged tents on parish churches in favour of the traditional five domes; the tradition of the tent survived in bell towers and in timber building, culminating in the Transfiguration church at Kizhi (1714), with twenty-two onion domes of aspen shingle. Peter the Great then turned Russian architecture decisively toward Western Europe. But the domed silhouette had become the image of Russia itself, and it returned in the revival churches of the nineteenth century.

Legacy

The two ideas of this chapter shaped the churches of the next thousand years. In the Latin West, the Romanesque and Gothic builders kept the long basilica, vaulted its nave and lifted its clerestory until the walls turned to glass. In the East, the dome on pendentives passed from Hagia Sophia to the Ottoman mosque, and the Byzantine church, through its daughters in the Balkans, the Caucasus and Russia, remains the form of Orthodox worship today. The Renaissance joined the two: its architects set a Byzantine dome on pendentives over the crossing of a Roman basilica, and called the result a return to antiquity.