The Mausoleum of Fatima Khatun was built by Sultan Qalawun for his wife Umm al-Salih in 1283-4. The shad al-'ama'ir (superintendent of royal constructions, usually an amir) was the Amir 'Alam al-Din Sanjar al-Shuja'i, whose constructions feature architectural and decorative features unprecedented in Cairene architecture.
The use of squinches filled in with keel-arched stalactite pendentives in the dome's zone of transition was a new development.
Sources:
Creswell, K.A.C. The Muslim Architecture of Egypt, vol. II. Hacker Art Books, New York, 1978.
Ibrahim, Laila 'Ali. "The Transitional Zones of Domes in Cairene Architecture." Kunst des Orients 10 (1975): 5-23.
Jarrar, Sabri, András Riedlmayer, and Jeffrey B. Spurr. Resources for the Study of Islamic Architecture. Cambridge, MA: Aga Khan Program for Islamic Architecture, 1994.
