A study of the life and background of Abd al-Qadir al-Jilani, putative founder of the Qadiriyya order, investigating the sources for his life and attributed works. The book seeks to elucidate the ideas of al-Jilani, and to formulate a picture of the most prominent trends of pious and mystical thought in Baghdad during the twelfth century, providing a cultural and geographical angle to the study of Islamic mysticism and piety.