THE BATTLE OF YARMUK 636: The battle of Yarmuk in 636 was the decisive event which opened Syria to the Arab armies. The Byzantines operating in unfamiliar terrain were outmaneuvered and their troops were driven down the rocky ravines to the river where many perished. After this defeat the emperor Heraclius abandoned Syria and withdrew beyond the Taurus Mountains.
In the 630s Arab armies had been making progress on the Syrian front. The course of events here seems to have been more complex than in Iraq and this may explain why there are a larger number of differing accounts. Apparently 633 saw little more than minor encounters with frontier garrisons. This changed with the arrival, probably in 634, of Khalid b. al-Walid from the Iraqi front. Khalid’s journey from one theatre of war to the other has aroused great interest among military historians because he seems to have moved his troops rapidly across a terrain of waterless desert generally believed to be impassable, and so surprised his enemies. As with so many events during this period, there are conflicting accounts. According to one version, he made his way up the Euphrates and along the old caravan route which led through Palmyra to Syria. This is a sensible route and it may have been the one he travelled, but early accounts all agree that his forces encountered great problems with thirst. It is said that they had to go six entirely waterless days and did not have enough skins to carry supplies. To solve this problem Khalid ordered that camels should be forced to drink great quantities of water and their mouths were bound to prevent them from chewing the cud. They were subsequently used as animated water-tankers, slaughtered as required and the water drunk from their stomachs. This may not sound very appetizing, but faced with the alternative of dying from thirst; the Muslim troops must have suppressed any queasiness they may have felt. The six-day march is said to have taken place between two wells whose names are given but which cannot now be identified with any certainty.
This story may be no more than a traditional tale which has been attached to Khalid’s name, but if true it can hardly have happened on the Palmyra route which is, by the standards of the Syrian desert, comparatively well watered. If we accept this, then it seems likely that Khalid may have travelled by the southern, alternative route through Dumat al-Jandal, a remote oasis lying about half-way between southern Iraq and Jordan. To lead an army by this route would be an extraordinary feat of daring. There are no other records of armies ever coming this way for the very good reason that it was waterless for long stretches. Even if Khalid’s force were no more than 500 to 800 strong, the most likely estimate, the feat still indicates a military leader of genius. It was the kind of long-range outflanking operation which Subedei was to perfect at the time of the Mongol conquests five hundred years later. The story of Khalid’s desert crossing is proof that the Muslims were able to use the desert to achieve mobility and surprise, and gain an advantage denied to their opponents. It also shows how the command in Medina could assert effective control over the conduct of field operations and order comf!1anders around as and when it deemed necessary.
The numbers in Khalid’s force may have been small, but their arrival seems to have transformed the position in Syria from a sideshow to a major field of conflict. According to one account, he surprised and routed the Christian Arabs of the Ghassanid tribe, the Byzantines’ m.ain allies in the area, as they were celebrating Easter, probably in 634. This surprise concentrated the mind of the Byzantine Emperor Heraclius on the threat that the Arabs now posed. This threat became more ominous as they began to take possession of cities along the desert margin such as Bostra and possibly Damascus, where many of the population were themselves already Arabic-speaking and may have been sympathetic to the invaders. Local Byzantine forces were defeated in battles at Ajnadayn and Pella in the Jordan valley.
Heraclius then gathered the largest army he had at his disposal, including many tough Armenian troops from the Caucasus area, and sent them to confront the Muslim armies at the River Yarmuk, on the present Jordanian-Syrian border. The battle of Yarmuk, which probably took place in August 636, is the only battle in the course of the Arab conquests where the sources enable us to reconstruct the conflict in any detail, although even here there are contradictions and confusions. It is also the only battle for which the site can be identified with any precision, the rocky landscape and deep wadis, as well as the remains of the Roman bridge, allowing us to plot the movements of the armies. The Muslim army may have numbered 20,000 men while the Byzantine forces were probably somewhat larger, even though Muslim accounts tend to talk up their numbers and represent the Arabs as fighting against enormous odds. Even before the battle, there seem to have been tensions among the Byzantine commanders and between the Byzantine army and the local inhabitants of the area, most of whom were Arabs even if they were not Muslims. It may be that the army had supply problems as a result.
At the start of the battle, the Byzantine forces advanced to Jabiya, the summer camping grounds of their Ghassanid allies. As the Muslims fell back, they moved up into the area between the wadis of Ruqqad and Allan, and their line may have become over-extended. It seems that the Muslim right tempted the Byzantine left wing to advance by feigning flight and that the Muslim cavalry managed to outflank the Byzantines. Khalid then drove a wedge between the Byzantine cavalry and infantry: A key tactical objective was achieved when the Muslims captured the only bridge across the Wadi’l Ruqqad, effectively cutting off the Byzantine retreat. It was at this point that Byzantine resistance began to crumble. Rumours were spread that the Ghassanids and their followers had fled. Uncertainty turned to panic and many Byzantine soldiers attempted to escape down the steep banks of the wadis and were driven to their deaths. A dust storm sprang up (it was high summer) obscuring much of the action, and the Byzantine army was largely destroyed.
The story of the battle of Yarmuk reveals much about the nature of Arab military success. Both in tactics and strategy, the Arabs were surprisingly conventional. There were no great tactical ideas, none of the overwhelming mustering of forces and movements of encirclement which characterized Mongol victories. There were no secret weapons. The Muslims drew up a battle line, with left wing, right wing and centre, just as their enemies did. An Arab general at the end of the seventh century described the progress of battle to his inexperienced troops before they encountered the enemy in the following words: ‘The first stage of fighting is the shooting of arrows, then the pointing of spears, then the thrusting of them to the left and right and finally the drawing of swords. That’s all there is to it.’ The Muslims may also have been more familiar with the landscape, though there is no evidence for this, and they may have been given help by local sympathizers, but again there is no proof. They simply fought a conventional battle and fought it better and more effectively than their enemies.
Just as the battle of Qadisiya laid open the rich lands of Iraq, so the defeat of the Byzantines at the Yarmuk enabled the Arabs to take control of Syria. The redoubtable Emperor Heraclius, veteran of so many triumphs and disasters, retired beyond the Taurus Mountains lamenting that he was leaving so sweet a land to his enemies. The towns and cities of Syria and Palestine were left to fend for themselves and few resisted for long. Antioch, the political capital, and holy Jerusalem had both fallen by the end of 638. Only Caesarea on the coast, which could be supplied from the sea, held out, probably until 641.