The basic strategy of early Muslim armies setting out to conquer foreign land was to exploit every possible drawback of the enemy army in order to achieve victory with minimum losses as the Rashidun army, quality-wise and strength-wise, was sub-standard to the Sassanid Persian army and the Byzantine army.
Once the Byzantines were weakened and the Sassanids effectively destroyed, the later Rashidun generals were free to use any strategy and tactics to overpower the opposing forces but they mainly relied on the mobility of their troops to prevent the concentration of enemy troops in large numbers [REF].