CHAPTER II

EARLY CHRISTIAN AND BYZANTINE ARCHITECTURE

When the “Peace of the Church” had been proclaimed by Constantine and Christians were able to worship openly, the age of church-building commenced, the Emperor himself setting a lead. After the edict of Theodosius, making Christianity the State religion, many of the pagan temples were adapted to the purposes of the Christian ritual, or their columns and decorative features were appropriated for the building of new churches. The former practice accounts for the preservation of the Parthenon, Erechtheion, and the Temple of Theseus at Athens. An instance of the method of conversion is to be traced in the =Cathedral of Syracuse, Sicily=, which occupies the site of an ancient temple. Walls were built between the Doric columns of the peristyle, while the walls of the cella were pierced so as to communicate with the peristyle, which thus served as aisles. Another instance is that of a temple in =Aphrodisias=, in Caria, Asia Minor, where the walls of the cella were entirely removed, and walls were built outside the peristyle to form aisles, while to increase the length of the nave the front and rear portico columns were set in line with the others.

=Basilican Plan.=--These changes coincided with the general adoption of the basilica plan in the case of new buildings. For the early Christian churches show very little regard for the appearance of the exterior. Attention was concentrated on the interior, in fitting it for ritual worship and in beautifying it, and to both these objects the basilica plan most readily contributed.

The earliest example in Rome of a church so planned is that of =St. John Lateran=, which, however, has been completely remodelled by subsequent additions. The next in point of time was the =Cathedral Church of St. Peter=, erected near the spot in which the saint was martyred in the circus of Nero. It was torn down in 1506 to make room for the present cathedral commenced by Julius II; but the appearance of its principal façade is known from Raphael’s mural painting “Incendio del Borgo,” in the stanze of the Vatican, and there is a record of its plan. The latter shows that the basilica building was approached by an atrium, surrounded by either colonnades or arcades, enclosing a rectangular space, open to the sky and having a fountain in the centre. With the water the worshippers sprinkled themselves, a symbol of purification still preserved in the “holy-water” vessel, placed inside the entrance of Roman Catholic churches.

The end arcade, abutting on the church proper, was used by penitents and called the _narthex_. The body of the church was divided, as in the basilica halls, into central nave and side aisles--the latter sometimes double. Across the end of the nave extended the _bema_ or sanctuary, corresponding to the space raised and enclosed for litigants and lawyers in the basilica. Its ends projected beyond the line of the main building, forming rudimentary transepts, which may have been used as sacristies for the robing of the clergy and the preservation of the sacred vessels and other ritual objects. The central part of the bema was elevated and occupied by the altar which was surmounted by a _baldachino_ or canopy, supported on four columns. Behind the altar was the apse, lined with seats; those of the Roman assessors being now occupied by the presbyters, while the centre one of the quæster or praetor became the bishop’s throne. For the transference of the latter to the side of the choir was of later date.

The officiating priest stood behind the altar, facing the congregation and the east. For as yet the main façade was not the western, a fact of interest when we recall that while the Hellenic architects built facing the four points of the compass and made the chief entrance on the east, the Romans were indifferent to the matter of orientation.

In certain instances as that of =S. Clemente=, in =Rome=, the accommodation for the choir projected from the bema into the nave. It was enclosed with low screen walls called _Cancelli_ (whence was derived the word chancel); the side walls projecting to afford space for two reading desks, or _ambones_; respectively, the Gospel _ambo_ and the Epistle _ambo_.

=Treatment of Columns.=--There were two ways of treating the columns. In the earlier type of churches, the aisles were spanned by arches, while those of the nave supported an entablature. But this necessitated a narrow intercolumniation, considerably obstructing the view. Accordingly, the practice ensued of placing the columns further apart and surmounting them with arches. The first example of this use of _arcades_ in a nave is believed to occur in the northern gallery of the =Palace of Diocletian= in =Spalato, Dalmatia=. Both methods continued to be employed and were sometimes combined in the same building. Over the entablature or arches, as the case might be, was a high stretch of wall, rising above the level of the aisle roof, pierced with a row of _clerestory_ windows. The nave and aisles terminated in arches, that of the former, the principal entrance to the sanctuary, being called the Arch of Triumph. The roofs were of timber; that of the nave rising to a ridge and finishing at each end in a gable, while a slope from below the clerestory covered the side aisles. The construction work of the roofs was usually hidden in the interior by flat ceilings, beamed and coffered.

The decoration of the interior included the use of antique columns, which were sometimes adapted to their new place by cutting down or removing the bases. The walls above the nave arcading or entablature were adorned with mosaics, which also embellished the space above the Arch of Triumph and the semi-dome of the apse. The floors were covered with geometric patterns of marble sliced from columns and other antique fragments.

The principal examples of basilican churches, still existing in =Rome=, are =St. Paul-without-the-walls=, =S. Clemente= and =S. Maria Maggiore=. The first named is of modern construction, completed in 1854, but preserves the plan and dimensions of the older church which was destroyed by fire in 1823. It had been begun in 380 by Theodosius, on a plan closely following that of the old St. Peter’s, except that the transepts of the bema project less and the atrium was abandoned, leaving only the narthex. Its construction and embellishment were continued by other emperors and by many popes, the munificence of the latter being commemorated in a series of portrait medallions of the popes which extends in a band above the arcade-arches on each side of the nave. The wall space above them is veneered with rare marbles, enclosing panels filled with paintings representing incidents in the life of St. Paul. Amid the somewhat extreme sumptuousness of the interior a feeling of the older character of a basilican church is preserved in the mosaics of the fifth century which adorn the arch of triumph, and in those of the apse which date from the early part of the thirteenth century.

=S. Maria Maggiore= presents an original basilican plan of nave and single aisles, from each of which during the Renaissance was built out a square side chapel, surmounted by domes, giving the plan the form of a cross. But the interior of the nave dates from the time of Sixtus III in the fourth century and shows on each side a series of Ionic columns, supporting an entablature. Above this, as also over the arch of triumph, are mosaics of the fifth century.

The =Church of S. Clemente= is notable for the retention of the atrium and also for the termination of the aisles in apses, a feature which suggests Byzantine influence.

=Circular and Polygonal Plans.=--In addition to the basilican buildings of this period were some which involved a circular or polygonal plan, suggested probably by the circular temples and tombs of the Romans. They were applied in the early Christian era both to tombs, which in some cases were afterward converted into churches, and to baptistries. The latter were independent buildings, so called from their use at first solely for the sacrament of baptism. In later times, however, it became the custom to place the font inside the church; yet as late as the eleventh century was erected the famous =Baptistry of Florence=, in which even to this day every child born within the city is baptised.

The examples in Rome of circular or polygonal buildings are the Baptistry which forms part of the group of buildings of =S. John Lateran=, the =Tomb of S. Constanza=, the daughter of Constantine, which was converted into a church in 1256, and the church of =S. Stefano Rotondo=.

The general character of the Roman tomb was a circular mass, superimposed on a square podium. The cylindrical mass was sometimes decorated with pilasters, supporting an entablature, and occasionally was surrounded by a peristyle, while its roof was apt to be conical.

In early Christian architecture this principle of construction was developed. The peristyle was enclosed by outer walls, and the lower part of the walls of the cylindrical mass was replaced by columns. Thus, in the =Baptistry of S. John=, which has been called the =Baptistry of Constantine=, the conical roof is supported by a circle of eight columns, in two stories.

The =Tomb of S. Constanza= has a dome which is supported on twelve pairs of granite columns, while the wall of the circular aisle is inset with sixteen recesses, alternately apsidal and rectangular in shape, one of the latter being opened through to form the entrance. The sarcophagus of the saint which formerly occupied one of the niches, is now in the Vatican Museum. Its sides are carved with genii gathering grapes--a motive which is also represented in the mosaics that adorn the vaulting of the church’s circular aisle.

=S. Stefano Rotondo=, though much reduced from its original size, is said to be still the largest circular church in existence. The wall of the cylinder, surmounted by a wooden conical roof, is supported on a circular entablature, carried by antique columns. It was surrounded, when built by Simplicius in the fifth century, by double circular aisles, covered by a sloping roof. The latter was supported by columns and arches, while the external wall was decorated with pilasters. Traces of these are still apparent; otherwise the outer aisle has disappeared and the present exterior represents the walling up of the spaces between the columns. This was done by Nicholas V in the fifteenth century, by which time the edifice, once richly decorated with marble veneers and mosaics, had fallen into decay. Its lateral walls are now covered with horribly naturalistic scenes of martyrdom, executed at the end of the seventeenth century.

=Syrian Examples.=--Syria has disclosed to explorers--of whom the late Marquis of Vogüé and Dr. H. C. Butler of the American Archæological Expedition have been the foremost--a number of interesting monuments, both civic and religious, erected between the third and eighth centuries. While details of moulding and ornament appear to have been copied from those of Roman remains, the methods of construction were worked out by the builders themselves. They seem to have retained the Phœnician preference for using the largest stones that could be quarried, transported, and put in place. Thus, arches were frequently carved out of a single stone, and when voussoirs were used, they were either few in number or, if numerous, of great height and depth. Large slabs of stone were also employed for roofing, especially in houses. In imitating antique details the architects appear to have had little if any feeling for their constructional origin or meaning; the capital and half the shaft of a column, for example, being carved out of one piece of stone, while the remainder of the shaft and the base were cut out of another. On the other hand, they developed for themselves certain fine features of construction, as for instance, in the arcading of their basilican churches, in which the columns were sometimes replaced by large rectangular piers, carrying arches of great width. An example of this impressive method is found in the interior of the =Church of Kalb-Lauzeh=. This corresponds with the larger =Church of Turmanin=, the western façade of which shows a very independent spirit of design. It has a broad arched entrance, flanked by two square towers, connected over the doorway by an open gallery, constructed with columns.

A corresponding inventiveness marked their use of the basilican plan. A fine example is the large =Church of S. Simeon Stylites= at =Kalat-Seman=. The nucleus of the plan is an octagonal court, open to the sky, in the centre of which stood the pillar on which the saint spent thirty years of his life. This court forms the intersection or crossing of four rectangular wings, arranged in shape of a cross, each one of which has a basilican form, the nave and aisles of the eastern one terminating in apses.

Another very interesting plan occurs in the =Cathedral at Borah=. It presents a circle inscribed in a square, in the angles of which are apsidal recesses projecting from the circle. Moreover, from the east side of the square project three short rectangles, terminating in apses, which suggest the prolongation of the nave and aisles that have been interrupted by the circle. Nothing but the foundations of this church remain. Meanwhile, the =Church of S. George= at =Esrah= shows a similar plan and is surmounted by a high elliptical dome. It is conjectured that these two churches were the prototypes of =S. Sergius, Constantinople=, and =S. Vitale= at =Ravenna=, which will be discussed later, and of many corresponding churches of Byzantine architecture.

=Ravenna.=--In the development of early Christian architecture a very interesting part was played by Ravenna. For this city, situated on the Adriatic (though the sea has since receded to a distance of six miles), was the chief port by which the trade of Constantinople or Byzantium entered Italy. Accordingly some of the tombs and churches present a fusion of Byzantine and Syrian influences with Roman. The change from the basilican type is especially marked in the character of the plan and by the adoption of domes.

Thus the =Baptistry of Ravenna= is an octagonal structure, surmounted by a dome of hollow tiles. The =Tomb of Galla Placidia= is cruciform in plan with a lantern raised over the crossing or intersection of the arms of the cross. The lantern is pierced with four windows and surmounted by a dome, supported on pendentives--a method of construction, peculiarly Byzantine, which will be considered presently.

When Theodoric the Great, King of the Ostro-Goths and ruler of Northern Italy, selected Ravenna as his capital, he built the =Church of S. Apollinare Nuovo=, importing twenty-four marble columns from Constantinople and employing Byzantine artists and artisans. The plan is basilican, though the atrium and apse have been removed by subsequent alterations, but the interior is richly embellished with Byzantine mosaics. The latter also adorn the larger basilican =Church of S. Apollinare-in-Classe=, so called from its being situated near the port. Its columns also are distinguished by the peculiarly Byzantine feature of the _impost block_, to be described later.

After the death of Theodoric in 536 the Emperor Justinian, having through his general, Belisarius, routed the Goths from the country, made Ravenna the political capital of Italy, under the authority of an exarch. Then was built, probably as Court Church, the famous example of Byzantine influence, the =Church of S. Vitale=. We will return to this after a consideration of what is involved in the Byzantine style.

=Byzantine.=--The term Byzantine is applied to the style of architecture gradually developed in Byzantium after Constantine, in A.D. 324, transferred the capital of the Roman Empire to that city. Its distinctive features are the use of brick and stone in place of concrete; the use of imposts in connection with columns and arches; the character of the carved ornament applied to surfaces and, most important of all, a system of covering rectangular spaces with domes. It reached its highest point of development under the Emperor Justinian, between the years 527 and 565.

The style was the result of evolution; a product of the combination of principles of construction derived from Roman, Early Christian and Syrian architecture, and from the traditional methods of the Iran builders of Assyria; affected in matters of decoration by the luxurious taste of the Orient.

The favourite material of Byzantine builders was brickwork; the bricks being one and one-half inches in thickness, like the Roman, and laid between layers of mortar of similar thickness. In the case of cornices the bricks were moulded to the required contours and when used for the shafts of columns were circular in outline. The mortar was composed of sand, lime, and crushed pottery, tiles, or bricks. Except in the case of marble columns which were cut and put in place by masons, the whole of the preliminary work was done by bricklayers who constructed the entire “carcass” of the building. When this

had dried and settled, the masons and the decorators completed the work, by overlaying the walls, domes, and pediments of the interior with marble or mosaics.

The floors were paved with richly coloured marbles, in _opus sectile_ or _opus Alexandrinum_. Marble, also, cut in thin veneers and arranged so that their veining produced symmetrical designs, was applied to the walls. Marble, again, but incised with carved ornament, covered the soffits of the arches, the archivolts, and spandrels, while the vaulting was resplendent with mosaics, composed of figures and ornaments, executed in enamelled glass upon a background of gold or blue or, more rarely, pale green.

Colour was pre-eminently the motive of the interior decoration and to this end carved work was subordinated. The ornament was in very low relief, spreading over the surface in intricate patterns, that suggest the delicate enrichment of lace. Mouldings were replaced by bands of mosaic or marble, carved or smooth. The chief motive of the carved ornamentation was the mingling of the acanthus and anthemion. The treatment of both was rather Hellenic than Roman; the foliage having pointed ends; but it was deeply channelled and drilled with deep holes at the springing of the leaves. In fact, the use of the drill as well as the chisel was characteristic of Byzantine carving and emphasises the suggestion of the ornament being raised rather than, as in Roman decoration, applied. Corresponding to the general flatness of the ornament is the constraint of the contours of the mouldings, suggestive of Asiatic languor and in marked contrast to the vigorous profiles of classic architecture. The impression, indeed, of the whole scheme of decoration is rather one of soft richness, as carving melts into colour and colour deepens and glows and finally passes into the gold or depths of azure of the vaulting.

When the supply of antique columns was exhausted the Byzantine architects began to imitate them, but soon departed from the classic type. In certain cases the capital retained something of its derivation from the Ionic or Corinthian styles; but gradually a new type was evolved, which was distinguished by being convex to the outside rather than concave. The motive appears to have been to give additional support to the arch, for which purpose an _impost_ was, as the name implies, “placed upon” the capital. It consists of a block, which projects beyond the edges of the capital to fit the extra thickness of the wall and may represent, as has been suggested, the survival of a part of the architrave of the discarded entablature. In the decoration of the capitals the foliage was sometimes enclosed in frames of interlace, or the latter took the form of a basket, on which birds are perching.

=Pendentive Dome.=--We have now to consider the most characteristic feature of Byzantine architecture--the Dome. Briefly, in the 200 years that divided Justinian from Constantine the Byzantine architects perfected a principle of dome construction by which they crowned a square plan with the circle of a dome.

The Romans confined their domes to circular or polygonal buildings. Meanwhile they had worked out the construction of groined vaulting upon four supports. The Byzantine achievement was to make four supports carry a dome. It was accomplished by developing the element of construction--the _pendentive_.

We have already noted the bas-relief found at Koyunjik, which shows that the Assyrians understood the crowning of small square buildings with domes. While actual examples have perished, the tradition of this construction seems to have survived in the East. For in the third century A.D. , when the Persians established the Sassanian Empire under the impulse of a movement that sought to restore the ideals and habits of the old national life, the builders erected domes in the palaces of Serbistan and Firuzabad.

The method they adopted was to bridge each angle of the square, at some distance below the top, with a small arch. On these they erected two small arches that projected beyond the face of the original arch and accordingly extended the width of the bridge. They continued this process of superimposing tier upon tier of arches, until the bridge was level with the top of the square, by which time the latter was transformed into an octagon. Then, by inserting a _corbel_ or bracket in each angle of the octagon and taking advantage of the thickness of the masonry, they were able to adjust a dome to the structure. This system of dome-support, we shall find, was adopted in Gothic architecture, where the arches are called _squinches_.

Another method of dome-support, found in the =Mosque of Damascus= and frequently employed in the churches of Asia Minor, was to bridge the angle with a semi-circular niche.

Meanwhile what the Byzantine architects developed was a geometrically exact system of converting the square into a circle by means of concave triangular members that are specifically called _pendentives_.

The character and function of a pendentive may be readily grasped by a practical experiment. Cut an orange into two hemispheres. Lay the flat of one on four reels, placed at the four angles of a square, inscribed within the circle. These reels represent the piers on which the pendentives are to be constructed. Now by four perpendicular incisions of the knife cut off the segments of the hemisphere that project beyond the square. The lateral spaces between the piers will now be spanned by four arches. Finally, a trifle above the top of the arches, make a horizontal cut, removing the upper part of the hemisphere. The rind which remains represents the four pendentives. The flesh inside of it may be likened to the timber centering used in the construction of the pendentives and, now that the latter are completed, may be removed. Remove also the flesh from inside the upper part of the hemisphere. It will then be a hollow cap, which you can replace on the top of the pendentives. You now have an instance of a dome and pendentives included in a single hemisphere. More usually, however, the architect makes the curve of the dome different from that of the pendentives. Frequently, too, to give the dome superior distinction, he constructs a cylindrical wall on the circle of the pendentives, and on this _drum_, as it is called, elevates his dome.

Scientifically stated: “If a hemisphere be cut by five planes, four perpendicular to its base and bounding a square inscribed therein, and the fifth parallel to the base and tangent to the semi-circular intersection made by the first four, there will remain of the original surface only four triangular spaces bounded by arcs of circles. These are called pendentives.” (Professor Hamlin.)

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The first church built by Justinian was =SS. Sergius and Bacchus= in =Constantinople=. The part dedicated to the latter saint--a small basilica--was destroyed by the Turks. The remainder presents the plan of a rectangle enclosing an octagon on which rests a dome of a curious, fluted, melon shape.

A few years later was erected the church of =S. Vitale= in =Ravenna=, probably as the Court Church. Its plan is an octagon within an octagon; the inner one being surmounted by a dome.

The domical arrangement of both these churches may have been originally derived from the =Pantheon=, modified by the example in Rome, of what is called the =Temple of Minerva Medica=, though it was probably a nymphæum. This building is decagonal with niches projecting from nine of the sides, while the tenth provides the entrance. The dome, of concrete ribbed with tiles, is built over an inner decagon of ten piers carrying ten arches. These in turn support a decagonal drum, pierced with windows, the angles at the top being filled in with rudimentary pendentives. The same principle of construction reappears in both =S. Sergius= and =S. Vitale=; the dome of the latter being composed, for the sake of lightness, of earthenware, amphora-shaped pots, the bottom of one being fixed in the lip of another. It is sheathed on the outside with a wooden roof.

This =Church of S. Vitale= became the model on which Charlemagne based his domical church at =Aix-la-Chapelle=, which was built as a royal tomb, A.D. 796-814, and was afterward used as the crowning-place of the Emperors of the West.

=S. Sophia.=--Finally, the pendentive system was fully developed in Justinian’s church in Constantinople dedicated to the =Holy Wisdom--Hagia Sophia=, called, though erroneously, =S. Sophia=. It marks the highest development of the Byzantine genius for domical construction.

The architects were Anthemius of Tralles and Isidorus of Miletus, who began the work in 532 and finished it in 537. The plan shows four mighty piers, 25 feet square, set at the angles of a square of 107 feet. These support four arches and intermediate pendentives of noble height, the apex of the dome being 175 feet from the pavement. For the original dome, having collapsed in 555, was replaced by a higher one, lighted by the introduction of forty circular-headed windows around the spring of the curve; an arrangement not only excellent in admitting light to the interior, but also as wonderfully impressive in its way as the single eye of the =Pantheon=. Rows of small circular headed windows are also pierced in the screens which fill in the north and south arches.

Abutting on the east and west arches of this central mass are semi-domes, supported upon the central piers and two others. And from these project, as in =S. Sergius= and =S. Vitale=, small semicircular domes, sustained by an upper and lower story of arcades. Thus was created a vast oval-ended hall, 267 feet long by 107, from every part of which the summit of the dome is visible.

Outside this central feature are two side-aisles, each having two stories, separated from the nave by arcading and formed of a series of columns and vaulting. As in all Early Christian and Byzantine churches which have upper and lower galleries, the former were occupied by women worshippers. The outer walls on the north and south sides, as the plan shows, are reinforced by immense buttresses, 25 feet wide and 75 long, which appear on the outside of the buildings like huge pylons. On the inside they are pierced with arches on each story. These buttresses withstand the thrust of the dome which is reinforced on the east and west by the semi-domes.

The edifice, which occupies practically a square, is approached on the west side by a narthex of magnificent proportions, 200 feet long by 30 wide, which is divided like the aisles into an upper and lower story. So far “the plan resembles that of =S. Sergius=, if the latter were cut in half and a dome on pendentives inserted over the intervening square and the whole doubled in size.” In front of the narthex, however, extends a second one, opening, as in some of the basilican churches, into an atrium.

The exterior walls are faced with alternate courses of brick and stone and the domes, all of which are visible, are covered with a sheathing of lead.

=S. Mark’s, Venice.=--=S. Sophia= is a marvel not only of construction but also of unity of design. It is in this respect, among others, that it is superior to =S. Mark’s= in =Venice=, which was erected by Byzantine builders at the end of the eleventh century. Venice, like Ravenna, was in close touch with Constantinople and when she determined to build a cathedral to her patron saint, to replace an earlier basilican church destroyed by fire, it was natural that she should look to that city for the character of the design as well as for artists and artisans to execute it. The actual model was the =Church= of the =Holy Apostles=, in Constantinople, founded by Constantine, rebuilt by Justinian, and destroyed by the Turks in 1463 to make room for the mosque of Sultan Mahomet II.

The plan is a Greek cross, that is to say, a cross with the four parts of practically equal length, grouped around a central square. Each of the five divisions is crowned by a dome, supported on pendentives and reinforced by transverse barrel vaults. The transept and choir domes are slightly smaller than the ones over the crossing and the nave, because of the restrictions of space caused by the chapel of S. Isadore in the north transept, the Ducal Palace on the south, and the retention of the apse of the ancient basilica. Originally all the domes were sheathed externally with lead, but at a later date were covered with the lead-sheathed wooden lanterns now existing. With their high-pitched curves and ornamental terminals they represent a serious deviation from the true Byzantine style.

A similar departure from the latter is exhibited in the west façade. This was completed in the fifteenth century and involves a curious mixture of Orientalism and fanciful Gothic with features, such as the clusters of columns in two tiers, flanking the five entrances, which serve no structural purpose and have no architectural justification. They are purely picturesque. But =S. Mark’s= was the city’s shrine, to which each succeeding century added some embellishment and often with more zeal than discretion.

It is the interior rather that commands our admiration. For notwithstanding certain distractions, even here, of later debased styles of mosaic, enough of the tenth and eleventh century embellishments remain to dignify the decoration. And in no other building in the world is there so marvellous an ensemble of coloured marbles, alabaster, and glass mosaics; or such subtleties, delicacies, and complexities of light and shadow.

=Greece and Russia.=--In Greece and Russia the Byzantine has continued to be the official style of the Greek Church. In Russia, however, many fantastic elements have been introduced, particularly the bulbous form of the domes.

As an example of domestic Byzantine architecture may be mentioned the =Monastery of Mount Athos= on a promontory of Saloniki, overlooking the Ægean Sea.

“In Armenia are also interesting examples of late Armeno-Byzantine architecture, showing applications to exterior carved detail of elaborate interlaced ornament, looking like a re-echo of Celtic M.SS. illumination, itself, no doubt, originating in Byzantine traditions.” (Hamlin.)