276
ʿALĪ AND MUʿĀWIYA
[CHAP. XL.
A.H. 37.
dangerously to assail the Empire, and as often beaten back. Ever and anon, for ages, these Khawārij "went forth" (as the name implies) on their desperate errand, a thorn in the side of the Caliphate, and a terror to the well-disposed.