ely decorated, the walls having dados or slabs of
different coloured marbles supplemented by mosaics, with which every
portion of the domes, semi-domes, and pendentives were also covered,
whilst the columns, in many cases of variegated marble, had beautifully
carved capitals of an infinite variety of design.

It is customary to divide the history of the development of Byzantine
architecture into two distinct periods, the first extending from the 4th
to the close of the 6th century, the second from the 8th to the 13th
century, there having been a pause between them during which no
buildings of any importance were erected owing to the wars which
convulsed alike the East and the West. As already stated, no actual
buildings belonging to the earlier portion of the first period remain,
but there exist in S. Vitale at Ravenna and still more in S. Sophia at
Constantinople unique examples of the golden age of Byzantine
architecture, the inspiring influence of which was felt throughout the
whole of Europe and the greater part of Asia. The former church, begun
about 526, is of octagonal plan, each division, except that containing
the choir, with an apse of its own, and though the interior has been
greatly spoiled by restoration, the general effect of the vaulted
roofing, marble casing of the walls, and mosaics of the eastern end is
extremely fine. San Vitale is, however, altogether excelled by the
world-famous S. Sophia, now the chief mosque of Constantinople, which
occupies the site of a basilica built under Constantine, that was burnt
down early in the reign of Justinian. The latter emperor at once ordered
the erection of its successor, appointing as architects Anthemios of
Thralles and Isodoros of Miletus.

Begun in 532 and completed in 537, S. Sophia is of very simple yet most
dignified external appearance, so symmetrical is the grouping of its
many domes and semi-domes, whilst the interior, though it has none of
the rich colouring usual in oriental buildings, is unsurpassed in the
harmony of its structural details, all of which lead up, as it were, to
the huge central dome, the lower portion of which is pierced with a
series of small windows throwing a flood of light upon the vast circular
space below. The general plan is square, but a fine narthex consisting
of two spacious halls one above the other projects slightly beyond the
actual church at the western end. The nave, which is 106 feet wide by
225 long, has a semicircula