Abu Ubaidah ibn al-Jarrah
After the conquest of Jerusalem, Caliph Umar went back to his capital city of Madinah and following the Caliph's instructions, Yazeed proceeded to Caesarea and once again laid siege to the port city. Amr bin al-A’as and Sharhabeel marched to reoccupy Palestine and Jordan, which was completed by the end of the year. Abu Ubaidah ibn al-Jarrah and Khalid ibn Walid, with an army of 17,000 men, set off from Jerusalem to conquer all of northern Syria.