The great Justinianic basilica of Hagia Sophia is the pinnacle of early Byzantine architecture, and recognized as one of the great architectural achievements of all time. Despite this, detailed analytical studies of the building are few. This remains surprisingly unstudied by scholars, when compared to monuments of comparable importance. The purpose of this dissertation is to begin studying the architectural sculpture in detail. The nave cornices of Hagia Sophia represent a complete and unstudied ensemble of Justinianic sculpture, the largest in existence. It is securely dated, and its context in the structure provides a wealth of information on the structural history of the building.