and Pietro Gagliardi added frescoes. The right side of the basilica was part of a Roman thermae, i. e. bath house, dating to the reign of the emperor Hadrian (AD 117–38). Interior On the wall behind the high altar are three paintings made in 1803 by Bernardino Nocchi representing (from left to right): St Timotheus, The Glory of St Pudentiana, and St Novatus. The mosaic in the apse is late antique, from around the end of the 4th century; it is regarded by different groups of scholars as dating to either the pontificate of Pope Siricius (384–399) or of Innocent I (401–417), and was heavily restored in the 16th century. It is among the oldest Christian mosaics in Rome and one of the most striking mosaics outside of Ravenna, deemed the most beautiful mosaic in Rome by the 19th-century historian Ferdinand Gregorovius. This mosaic is remarkable for its iconography. Christ is represented as a human figure rather than as a symbol, such as lamb or the good shepherd, as he was in very early Christian images. The regal nature of this representation prefigures the majestic bearing of Christ as depicted in Byzantine mosaics. Christ sits on a jewel encrusted throne, wearing a golden toga with a purple trim (a sign of imperial authority and emphasizing the authority of Christ and his church). He poses as a classical Roman teacher with his right hand extended. Christ wears a halo and holds in his left hand the text: "Dominus conservator ecclesiae Pudentianae" (The Lord is the preserver of the church of Pudentiana). He sits among his apostles, two of whom were removed during restoration. The apostles wear senatorial togas. They all have individual expressions and face the spectator. The lower part of the mosaic was removed during the restoration in the late 16th century. The depictions of the apostles on the right side have been lost in the course of time and have been replaced by new, but rather blank, mosaics. Two female figures (representing "Church" and "Synagogue") hold a wreath above the head of Peter and Paul. Above them the roofs and domes of heavenly Jerusalem (or, in another interpretation, the churches built by the emperor Constantine in Jerusalem) are depicted. Above Christ stands a large jewel encrusted cross on a hill (Golgotha), as a sign of the triumph of Christ, amidst the Christian symbols of the Four Evangelists. These iconographic