This appeal to the Muslims’ inherent zeal, along with Khalid’s canny cavalry tactics, chronic Byzantine internal dissensions, a plague outbreak, and a massive dust storm combined to grant victory to the Arab upstarts. Writing around four thousand kilometers away and a couple of decades later, one Frankish chronicler, well informed about eastern affairs, lamented that at the battle of Yarmuk, “the army of Heraclius was smitten by the sword of the Lord.”8 God had picked sides, and it seemed his favor belonged to the armies of Islam.
