The apse mosaic in the Basilica of St. Pudentiana in Rome. In this mosaic dating to about 400 A.D., Jerusalem’s major Christian landmarks of that time appear on either side of the head of “Christ the Master.” To the left is the round Anastasis built over the tomb of Jesus and now incorporated within the Church of the Holy Sepulchre. To the right of the round Anastasis is the Constantinian Church of the Martyrion, built as a Roman-style basilica. To the right of Christ’s head, the pointed-roof structure is identified as the first Byzantine church on Mt. Zion, built by Theodosius I in the late fourth century. This church was probably octagonal, a form used for Christian memorial churches. The Theodosian church memorialized the mother of all churches on Mt. Zion, the Church of the Apostles, the original Judeo-Christian synagogue. This earliest, apostolic church-synagogue was left untouched by the Theodosian church and appears in this mosaic to the right of, and adjacent to, the new octagonal church.