After capturing Emesa, the Muslims moved north to capture whole of the northern Syria. Khalid, acting as an advance guard took his mobile guard to raid northern Syria. At Shaizer, Khalid intercepted a convoy taking provisions for Chalcis. The prisoners were interrogated and informed him about Emperor Heraclius' ambitious plan to take back Syria. They told him that an army, possibly 200,000 strong, would soon emerge to recapture their territory. Khalid stopped there. After his past experiences, Heraclius, now had been avoiding pitch battles with the Muslims. He planned to send massive reinforcements to all the major cities and isolate the Muslim corps from each other, and thus separately encircle and destroy the Muslim armies. Five massive armies were launched in June 636 to roll back Syria.