The Nizamiyya Madrassa of Baghdad was founded by:

Nizam-ul-Mulk Tusi was the Seljuq vizier who founded the Nizamiyya madrassas in the 11th century. These became model institutions of higher Islamic learning. Imam Ghazali was a famous teacher at the Nizamiyya, not its founder. Harun al-Rashid was an Abbasid caliph, and Ibn Khaldun was a later historian and philosopher.