 They penetrated into northern Syria near its borders with Anatolia intending to capture Antioch, and to secure the conquered lands from any possible threat from the north.After the conquest of Aleppo, Abu Ubaidah ibn al-Jarrah sent a column under Malik al-Ashtar to capture Azaz in Northern Syria, east of the Taurus Mountains.The capture and clearance of Azaz was essential to ensure that no large Byzantine forces remained north of Aleppo, from where they could strike at the flank and rear of the Rashidun army during the operation against Antioch.