The Alâeddin Mosque is the oldest mosque in Ankara. It has a carved walnut mimber, the inscription on which records that the mosque was completed in early AH 574 (which corresponds to the summer of 1178 AD) and was built by the Seljuk prince Muhiddin Mesud Şah (died 1204), the Bey of Ankara, who was the son of the Anatolian Seljuk sultan Kılıç Arslan II (reigned 1156–1192.)