Columbia subject headings:
Harvard subject headings:
Abbasids--History.
Islamic Empire--History--750-1258.
ʻAlī ibn Abī Ṭālib, Caliph, approximately 600-661--Imamate.
Princeton subject headings:
Abbasids--History.
Islamic Empire--History--750-1258.
ʻAlī ibn Abī Ṭālib, Caliph, approximately 600-661--Imamate.