 An ancient pagan altar was placed in the atrium in front of the church, and an early Christian mosaic was found on the site.The apsis mosaic dates to the 6th century and shows Christ (in black clothing with gold lati clavi, which on Roman garments indicated high rank) seated on an orb representing the heavens, flanked by Peter and Paul and by the two martyrs Theodore (a later addition, from Nicholas V's restoration) and Cleonicus.The church is also traditionally one of the seven original deaconries in Rome, being assigned to a deacon by Pope Agatho ("ca."