Al-Nizamiyya of Baghdad (Arabic: المدرسة النظامية‎), one of the first nezamiyehs,^[1] was established in 1065. In July 1091, Nizam al-Mulk appointed the 33-year-old Al-Ghazali as a professor of the school.^[2] Offering free education,^[3] it has been described as the "largest university of the Medieval world".^[4] Ibn Tumart, founder of the Berber Almohad dynasty, reputedly attended the school and studied under al-Ghazali.^[5] Nizam al-Mulk's son-in-law Mughatil ibn Bakri was also employed by the school. In 1096, when al-Ghazali left the nezamiyeh, it housed 3000 students.^[6] In 1116, Muhammad al-Shahrastani taught at the nezamiyeh.^[7] In the 1170s, statesman Beha Ud-Din taught at the nezamiyeh, before he moved on to teach in Mosul.