History and Monuments.— The germs of the style are seen in certain early Christian buildings in Syria and in Diocletian's palace at Spalato, which was probably built by Syrian or Byzantine workmen; more clearly in two 5th century buildings at Ravenna the baptistery of the Orthodox, having a dome over an octagonal substructure and the tomb of Galla Placidia, a cruciform edifice with a square (lantern) rising above the arms at their intersection, crowned by a dome on rudimentary pendentives. Doubt less, however, the original prototype of one class of Byzantine churches having a central square or octagon surrounded by an aisle is to be found in two Roman buildings erected by Constantine—the baptistery of the Lateran and the tomb of Constantia (Santa Costanza). The roof of the high central part of the former was of wood; of the latter, a masonry dome. The evolution of the central space with a dome on eight supports may be traced through early examples in Syria to Saint Sergius at Con stantinople (520 A.D.) where alternate sides of the octagon were occupied by open columnar niches or apsidioles projecting into the sur rounding aisle, thence to San Vitale at Ravenna (525 or 527), where there are six such apsidi oles; the easternmost bay being in both these churches extended to form a chancel and apse; and finally to its culmination in the new type of plan seen in Hagia Sophia (The Divine Wisdom, often called 'Saint Sophie; now a mosque). This extraordinary edifice, the work of two architects from Asia Minor, Anthemius and Isodorus, was built under the orders of Jus tinian in six years (532-38) to replace an earlier church destroyed by fire during a race course riot. It occupies a broad rectangle, measuring nearly 300 by 240 feet, and consists of a central nave 243 by 115 feet covered by a dome 107 feet in diameter and 180 feet high, and two half-domes of 100 feet span opening into the two transverse arches of the four that carry the dome. This hall is flanked by two vast aisles, 60 feet wide, each divided into three parts by two massive buttresses which rise above the roofs of the two-storied aisles. This triple division of the aisles by transverse buttress masses which rise above the aisle roofs is plainly derived from the traditional form and construction of the Roman thermm, probably through the intermediary Basilica of Maxentius of the early 4th century. A narthex across the west front preceded by an atrium or fore-court, and the projection of the apse at the east end, make up the total length of 300 feet. Open columnar apsidioles expand the semi-circular ends of the nave, and recall the six similar apsidioles between the piers of San Vitale at Ravenna. The interior is resplendent with pol ished columns of costly marble, verd-antique and porphyry, with marble wainscot and superb mosaics, though all human figures have been concealed by gilding and paint on account of Moslem prejudices. The furniture of the church, which was of unrivaled cost and splen dor, disappeared centuries ago. In this stupen dous work we seem to see the plan of Saint Sergius cut in two and between the two halves an immense square interposed, covered by a gigantic dome on pendentives rising far above the rest of the building. On the other hand, the cruciform type first shown in the tomb of Galla Placidia culminated, also in Justinian's time, in the church of the Apostles at Constan tinople. This had five domes, one on each arm of the cross and a central dome dominating the whole. This splendid church was demolished in 1463 by the conquering Sultan Mehemet II, but it had already served as the model for the builders of Saint Mark's at Venice.
With the exception of this last named church, none of the other Byzantine churches of Constantinople was of large size. The only other church of Justinian's time that has sur vived to our day is that of the Holy Peace, Hagia Eirene (miscalled 'Saint Irene'), now used as a museum of arms. It is, however, a
poor example, destitute of all embellishments, and is really a late (8th century?) and hasty reconstruction of the original edifice. With its two domes it may have served as the model for the Cathedral of Cabors, France. The later ex amples of the style in Constantinople were relatively small in scale, sometimes complex in plan, with small domes on high drums (Saint Theodore, Pantokrator, Mone tes Choras, etc.). About 40 of these small churches are extant, mostly transformed into mosques; and only one of them retains any considerable part of its original decorations. This one is the Mone tes Choras, now known as Kahrie Jami, dating probably from the 11th or 12th century, with a narthex adorned with mosaics and frescoes which, uncovered about 1880, the Turks have allowed to remain exposed. There are a num ber of late Byzantine churches in Athens— all of singularly small size— and at Salonica sev eral of various dates (Saint George, Saint Elias, Saint Bardias. Saint Sophia) • besides interesting monastic groups in Macedonia, at Meteora and on Mount Athos. In Russian Armenia (Ani, Etchmiadzin, etc.) the style took on a distinct provincial character, with stone pyramids instead of domes as the outer form of the cupola on a high drum, and often with highly interesting carved interlace orna ment. The singular and barbarously fantastic forms of shurches at Moscow, Kiev and other Russian cities (e.g., the Saint Basil in the Krem lin in Moscow) are remotely derived from the tall-drum domed 'lanterns' of the late Byzan tine type. Near the middle of the 11th cen tury the destruction by fire of the church of Saint Mark at Venice turned the attention of the Venetians toward Constantinople as the source from which to obtain architects and dec orators capable of rebuilding worthily the ven erated shrine of the evangelist. Architecture was at that time in Italy only beginning to revive from its low estate, and the native artists and the native art appeared inadequate for the task in hand, except as they were guided and assisted by Byzantine architects. The new church, measuring about 220 by 180 feet, was erected on the cruciform plan of the Holy Apostles' Church at Constantinople, with five domes, of which the central was slightly larger than those on the four arms. The very active Venetian commerce with the East brought in an extraordinary wealth of artistic material antique columns, veined marbles, carvings from ruined or dismantled churches — and with these and the embellishments of mosaic by Greek artists and their Italian pupils, as well as by later additions of sculpture and furnish ings, the interior was made resplendent beyond any other church in Italy or western Europe. Lacking the overwhelming majesty and unity of Hagia Sophia, it has nevertheless an extraor dinary beauty of its own. The main construc tion was completed in 1071; the domed narthex dates from the 12th century, with the extraor dinary and marvelously picturesque façade; the wooden exterior domes and Gothic pin nacles were added in the 15th century: some of the mosaics are modern. Unlike the Byzantine churches of the East, which almost wholly lack external embellishment, Saint Mark's is revetted externally with paneling of fine marble. Strange to say, it was never copied or imitated, except in the Romanesque church of Saint Front at Perigueux (France), which however is totally lacking in the embellishments of marble and mosaic that make up so much of the splendor of the Venetian model. Quite as sur prising is the fact that Hagia Sophia, the noblest of all Byzantine monuments, remained absolutely unique and unimitated until the Turkish conquest. It was the Turkish mosque builders who seized upon its superb possibilities and developed from them a new and splendid type of architecture for their own requirements (see MOHAMMEDAN ART).