One of the towering figures of medieval Sufism is Shihab al-Din Abu Hafs ‘Umar Suhrawardi, who was born in 1145 into a family that was steeped in the tradition of Sufism. His maternal uncle was Abu'l- Najib Suhrawardi (d. 1168) who had been one of the most influential and well-known Sufis of the time and, as shall be argued below, had a lasting impact on his nephew. The influence of Abu'l-Najib cannot be overestimated, and indicative of this is that Abu Hafs studied courses at the Nizamiyya, the leading religious educational centre in Baghdad where his uncle was professor of fiqh, and that Abu'l-Najib also initiated his nephew into Sufism and continued to nurture him in the esoteric dimension of Islam at his ribat by the river Tigris. In Baghdad, the capital of the caliphate, the younger Suhrawardi would have had access to great libraries and the teachings of other scholars of Islam. Another major influence upon him was the Hanbali preacher and Sufi ‘Abd al-Qadir al-Jilani, whose legacy may have resulted in Suhrawardi's antipathy to rational theology and logical reasoning (qiyas). In addition, it has been argued that Suhrawardi also disliked the metaphysical speculation that was promoted by the likes of Ibn ‘Arabi (d. 1240). In 1168 Suhrawardi's uncle passed away, so he commenced preaching in Abu'l-Najib's ribat in Baghdad and soon attracted large numbers to his sermons and speeches.