Al-Sayeda Zainab Mosque (Arabic: مسجد السيدة زينب) is a historic mosque in Cairo, Egypt, and constitutes one of the most important and biggest mosques in the history of Egypt. The name is an honor to Sayyida Zaynab bint Ali, one of the daughters of ‘Ali, fourth Caliph and first Shia Imam, and his first wife Fatimah, the daughter of the Islamic prophet Muhammad.