Khalid had 5,000 cavalry and 10,000 infantry with him. Knowing that his cavalry outnumbered the Persian cavalry, he designed his grand manoeuvre. His plan was the total encirclement of the Persian army using his superior cavalry. Rather than launching his cavalry via the flanks (as Hannibal had done in the Battle of Cannae), Khalid made use of the terrain, and positioned a part of the cavalry behind the western ridge of the battlefield. Khalid divided his cavalry into two regiments of about 2,000 men each, sending them behind the western ridge the night before the battle. They were instructed to attack the Persian rear at Khalid’s signal.