Christian Centralized and Domed Architecture
THE CHIEF MERIT of the basilica! church is its simplicity. With its clean lines and lack of any obvious architectural artifice, no basilica can ever be vulgar. Yet, even at its best, in such churches as S. Maria Maggiore or S. Apollinare in Classe, the plan has limitations. Once provided with a dome, however, the basilica is transformed; so transformed indeed, that it is a domed basilica, the church of St Sophia in Constantinople, that marks the zenith in Christian architectural achievement of any place or age. This unique achievement was made possible by the genius of its two architects, Isidorus of Miletus and Anthemius of Tralles, working under the patronage of Justinian; but before that time the stage had been set, by experiments aimed at the fusion of two distinct architectural ideas--that of the long-aisled Hellenistic basilica described above, and the centralized building, often roofed with a dome.
While the emphasis of the basilical church lies along its main horizontal axis, and so on the sanctuary, in the centralized building it is precisely the reverse, and the structure is rhythamically, and sometimes symmetrically ordered round the central vertical axis. Thus the centralized building par excellence is of circular plan, with its roof logically, though not of necessity, a dome. That such buildings are known in the East as well as in the West, and in particular that they existed in the Hellenistic cities of the Eastern Mediterranean, has led some scholars to join in the familiar game of 'Hunt the Oriental Prototype'. and to deny to Rome an original contribution in the field of domical architecture. In fact, while the construction of