The Battle of the great Zab river

The Abbasid revolution culminated in an epic battle amongst the fertile lands surrounding the Zab River, the white and black banners soared as the two armies clashed. Despite being outnumbered the Abbasid army had great confidence after a string of victories in previous battles. However this time the Umayyad host was led by the Umayyad Caliph Marwan himself known for being a stubborn warrior, he led the ferocious Syrian heavy cavalry on a head-on charge against the Abbasid spear wall a tactic which they have learned from the Syrians themselves. In this battle, the black banners soared and the white banners cast low.
The Umayyads were decisively defeated, Caliph Marwan fled to Egypt but was assassinated.