Alterations by Constantine
Because the defeat of Maxentius occurred before the basilica was completed, Constantine had the opportunity to make some significant changes to the design. Maxentius’ design included only one apse on the south side of the basilica. Constantine added the additional apse on the north side, as well as an open columned porch on the south side. His additional apse was added in order to accommodate the 30ft statue of himself Constantine commissioned to replace the portrait of Maxentius that had previously stood in the basilica. The adding a second apse completely undermined Maxentius’ original design, and allowed Constantine more significant ownership over the basilica.
Diana E. E. Kleiner, Roman sculpture (New Haven: Yale University Press, 1992).