A study of the life and background of ¿Abd al-Q¿dir al-J¿l¿n¿, putative founder of the Q¿diriyya order, investigating the sources for his life and attributed works. The book seeks to elucidate the ideas of al-J¿l¿n¿, 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.