The first renovation in the 20th century occurred in 1922, when the Supreme Muslim Council under Amin al-Husayni (the Grand Mufti of Jerusalem) commissioned Turkish architect Ahmet Kemalettin Bey to restore al-Aqsa Mosque and the monuments in its precincts. The council also commissioned British architects, Egyptian engineering experts and local officials to contribute to and oversee the repairs and additions which were carried out in 1924–25 by Kemalettin. The renovations included reinforcing the mosque's ancient Umayyad foundations, rectifying the interior columns, replacing the beams, erecting a scaffolding, conserving the arches and drum of the main dome's interior, rebuilding the southern wall, and replacing timber in the central nave with a slab of concrete. The renovations also revealed Fatimid-era mosaics and inscriptions on the interior arches that had been covered with plasterwork. The arches were decorated with gold and green-tinted gypsum and their timber tie beams were replaced with brass. A quarter of the stained glass windows also were carefully renewed so as to preserve their original Abbasid and Fatimid designs. Severe damage was caused by the 1837 and 1927 earthquakes, but the mosque was repaired in 1938 and 1942.