The first major study of the relationship between army and society in the early Islamic period, which reveals the pivotal role of the military in politics and offers a timely reassessment of the early Islamic State.

During the Medieval period, the Middle East was a battleground in which the Umayyad and the Abbasids Caliphs fought for dominance of an empire that stretched from Spain to the borders of India. The Armies of the Caliphs is the first major study of the relationship between army and society in the early Islamic period, and reveals the pivotal role of the military in politics.