Ecclesiastical architects in Constantinople have adopted the central plan for large-scale churches, in contrast to the horizontally oriented Christian basilica preferred by church architects in the West.

Their use of a succession of domes and half-domes, dependent on one another for receiving the thrusts (as in the Church of Saints Sergius and Bacchus in Constantinople, begun in 527 and completed in 536; now called Little Hagia Sophia), achieve a remarkable flow of interior space.

The light entering the windows at the base of the dome optically blurs the supports, with the extensive use of pendentives producing the effect of an airy canopy.

Saints Sergius and Bacchus exemplify the centralized plans beginning to be used for congregational churches as well as for martyrs' shrines, probably because of the growing importance of the cult of relics.