Siege of Germanicia The Siege of Germanicia or Marash was led by Muslim forces of the Rashidun Caliphate during their campaigns in Anatolia in 638 . The city surrendered without much bloodshed . This expedition is important because it marks the end of the military career of the legendary Arab Muslim general Khalid ibn Walid , who was dismissed from the army a few months after his return from the expedition . Background . The Muslims won a decisive victory at the Battle of Yarmouk fought in August 636 , thus the attempt made by the Byzantine emperor Heraclius to roll back Roman Syria failed . Further , unable to send more imperial troops to Syria , Heraclius made yet another attempt to re - conquer Syria by the aid of his Christian Arab allies of Jazira . The army of the Christian Arabs laid siege to Emesa in mid - summer of 638 . The Muslims avoided a battle in the open and instead opted for a defensive strategy which led to the Battle at Emesa . All the regiments from outposts in northern Syria were called to Emesa . The Christian Arab Army was forced to withdraw their siege when , by the orders of Caliph Umar , the Muslim army from Iraq attacked Jazira . At this point , the rear elements of the sieging army were attacked by a Mobile guard led by Khalid ibn Walid , which in effect left the Byzantine forces devastated . Caliph Umar then launched a full - scale invasion of Jazira which was completed without much resistance in just a few months . As soon as the western part of Jazira was occupied , Abu Ubaidah ibn al - Jarrah wrote to Umar and asked for Ayadh bin Ghanam , who was operating in western Jazira , to be put under his command so that he could use him in raids across the northern border . Umar agreed to this request , and Ayadh moved to Emesa with a part of the Muslim forces sent from Iraq to Jazira . The siege . In the Autumn of 638 , Abu Ubaidah launched several columns , including two commanded by Khalid ibn Walid and Ayadh , to raid Byzantine territory in Anatolia as far west as Tarsus . Khalid ' s objective was Germanicia ( Arabic : Marash ) , the city which lies on a plain at the foot of the Taurus Mountains . The region is best known for its production of salep , a flour made from dried orchid tubers . In late 638 the Muslim army laid the siege to the city which contained a Byzantine garrison . Expecting no help from their Emperor , the Byzantine garrison surrendered the city on the usual terms of Jizya offered by the Rashidun army , which included terms stating that the garrison and the populace be spared . As for material wealth , the Muslim could take all they wished . Aftermath . It is narrated that Khalid returned to Qinnasrin laden with spoils of war that had seldom been seen before . Many Muslim historians commented that " Just the spoils of Marash were sufficient to make the soldiers of this expedition rich for life " . Khalid ibn Walid , who was at the peak of his military career was unfortunately dismissed by Caliph Umar because of his immense popularity which was a result of his very successful military career . It was a general view that Umar had dismissed Khalid because he was angry with Khalid , though it was clarified later by Caliph Umar that : Khalid was urged by many of his companions to retaliate against Umar for this . Khalid did not , although he was powerful enough to launch a coup d ' état against Umar and in effect seize the power of the Rashidun Empire . He instead chose to stay away from politics and died four years later in 642 in Emesa . Caliph Umar was said to have felt embarrassed for his conduct against Khalid and was reported to have said at his death that ' he would have appointed Khalid as his successor if he was still alive . '