Islamic architecture on the culture of Norman Sicily. A frieze bearing a dedicatory inscription runs along the top of the exterior walls; although its text is in Greek, its architectural form references the Islamic architecture of north Africa. The recessed niches on the exterior walls are likewise derive from the Islamic architectural tradition. In the interior, a series of wooden beams at the base of the dome bear a painted inscription in Arabic; the text is derived from the Christian liturgy (the Epinikios Hymn and the Great Doxology). The church also boasted an elaborate pair of carved wooden doors, today installed in the south façade of the western extension, which relate strongly to the artistic traditions of Fatimid north Africa. On account of these "Arabic" elements, the Martorana has been compared with its Palermitan contemporary, the Cappella Palatina, which exhibits a similar hybrid of Byzantine and Islamic forms. Interior The church is renowned for its 12th century mosaics executed by craftsmen working in the Byzantine style. The mosaics show many iconographic and formal similarities to the roughly contemporary programs in the Cappella Palatina, in Monreale Cathedral and in Cefalù Cathedral, although they were probably executed by a distinct atelier. The walls display two mosaics taken from the original Norman façade, depicting King Roger II, George of Antioch's lord, receiving the crown of Sicily from Jesus, and, on the northern side of the aisle, George himself, at the feet of the Virgin. The depiction of Roger was highly significant in terms of its iconography. In Western Christian tradition, kings were customarily crowned by the Pope or his representatives; however, Roger is shown in Byzantine dress being crowned by Jesus in the Byzantine fashion. Roger was renowned for presenting himself as an emperor during his reign, being addressed as basileus ("king" in koine Greek). The mosaic of the crowning of Roger carries a Latin inscription written in koine Greek characters (Rogerios Rex ΡΟΓΕΡΙΟΣ ΡΗΞ "king Roger"). The nave dome is occupied by the traditional byzantine image of Christ Pantokrator surrounded by the archangel saints: Michael, Gabriel, Raphael and Uriel. The register below depicts the eight prophets of the Old Testament and, in the pendentives, the four evangelists of the New Testament. The nave vault depicts the Nativity and the Death of the Virgin. The newer part of the church is decorated with later frescoes of comparatively little artistic significance. The frescoes in