ial portraits on the coins
of the fourth century with those of the principate up to the dynasty of
the Severi reveals the same decline in taste and artistic ability.

In the realm of art as in literature Christianity supplied a new creative
impulse, which made itself felt in the adaptation of pagan artistic forms
to Christian purposes. The earliest traces of Christian art are to be
found in the mural paintings of the underground burial vaults and chapels
of the Roman catacombs, and in the sculptured reliefs which adorned the
sarcophagi of the wealthy. These were popular branches of contemporary art
and the influence of Christianity consisted in the artistic representation
of biblical subjects and the employment of Christian symbolical motives.
These forms of Christian art decayed with the general cultural decline
that followed the third century.

The most important and original contribution of Christianity to the art of
the late empire was in the development of church architecture. To meet the
needs of the Christian church service, which included the opportunity to
address large audiences, there arose the Christian basilica, which took
its name from the earlier profane structures erected to serve as places
for the conduct of public business, but which differed considerably from
them in its construction. In general the basilica was a long rectangular
building, divided by rows of columns into a central hall or nave and two
side halls or aisles. The walls of the nave rose above the roof of the
aisles, and allowed space for windows. The roof was flat or gabled, and,
like the wall spaces, covered with paintings or mosaics. The rear of the
structure was a semicircular apse which held the seats of the bishop and
the lower clergy. To the original plan there came to be added the
transept, a hall at right angles to the main structure between it and the
apse. This gave the basilica its later customary crosslike form.

While the basilica became the almost universal form of church architecture
in Italy and the West, in the East preference was shown for round or
polygonal structures with a central dome, an outgrowth of the Roman
rotunda, which was first put to Christian uses in tombs and grave chapels.
A rich variety of types, combining the central dome with other
architectural features arose in the cities of Asia and Egypt. The
masterpiece of this style was the church of St. Sophia erected by
Justinian in Constantinople in 537 A. D