A single horse led to the Byzantine Empire's massive defeat in the Battle of Achelous.

Byzantine commander, Leo Phokas 'the Elder' had the Battle of Achelous won. His opponent, Tsar Symeon of Bulgaria, was retreating and slowly withdrawing his men from the battlefield. How did a horse and water drastically change the battle, leading to Symeon's overwhelming victory over the Byzantine Empire?

Read more about this strange occurrence here in my article at warhistoryonline.com.