The Mosque of Sultan al-Mu'ayyad is a Mosque in Cairo Egypt next to Bab Zuwayla built by the Mamluk sultan Al-Mu'ayyad Sayf ad-Din Shaykh from whom it takes its name Construction began in 1415 and the mosque was completed in 1421 The complex included a Friday mosque and a madrasa for four madhhabs It replaced a prison which originally stood next to Bab Zuwayla