The Dome of the Rock's architecture and mosaics were patterned after nearby Byzantine churches and palaces. The supervisor and engineer in charge of the project were Raja ibn Haywa, Yazid ibn Salam, and the latter's son Baha. Raja was a Muslim theologian and native of Beisan, and Yazid and Baha were "mawali" (non-Arab, Muslim converts; clients) of Abd al-Malik from Jerusalem. Abd al-Malik was represented in the supervision of the construction by his son Sa'id al-Khayr. The Caliph employed expert works from across his domain, at the time restricted to Syria and Egypt, who were presumably Christians. Construction cost was reportedly seven times the yearly tax income of Egypt. The historian K. A. C. Creswell noted that those who built the shrine used the measurements of the Church of the Holy Sepulchre. The diameter of the dome of the shrine is and its height , while the diameter of the dome of the Church of the Holy Sepulchre is and its height .