The Battle of the Yarmuk (Yarmouk) 636 AD

Illustration of the Battle of Yarmuk by an anonymous Catalonian illustrator (c. 1310–1325)

The Battle of the Yarmuk (also spelled Yarmouk) was a major battle between the army of the Byzantine Empire and the Muslim forces of the Rashidun Caliphate. The battle consisted of a series of engagements that lasted for six days in August 636, near the Yarmouk River, along what are now the borders of Syria–Jordan and Syria-Israel, southeast of the Sea of Galilee. The result of the battle was a complete Muslim victory that ended Byzantine rule in Syria. The Battle of the Yarmuk is regarded as one of the most decisive battles in military history, and it marked the first great wave of early Muslim conquests after the death of the Islamic prophet Muhammad, heralding the rapid advance of Islam into the then-Christian Levant.

Date

 15–20 August 636

Location 

Near the Yarmuk River, in Syria

Coordinates

32.8141°N 35.9548°E

Result

 Rashidun Caliphate victory

The Levant is annexed by the Rashidun Caliphate

Belligerents

Rashidun Caliphate

 

Byzantine Empire

Ghassanid Kingdom

Tanukhids

Combatants

Rashidun Caliphate

Khalid ibn al-Walid

Abu Ubayda ibn al-Jarrah

Amr ibn al-As

Zubayr ibn al-Awwam

Malik al-Ashtar

Khawlah bint al-Azwar

Shurahbil ibn Hasana

Yazid ibn Abi Sufyan

Al-Qa'qa' ibn 'Amr al-Tamimi

Amru bin Ma'adi Yakrib

Iyad ibn Ghanm

Dhiraar bin Al-Azwar

Abd al-Rahman ibn Abi Bakr

 Byzantine Empire

 Theodore Trithyrius †

 Vahan †

 Jabalah ibn al-Aiham

 Dairjan †

 Niketas the Persian

 Buccinator (Qanatir)

 Gregory

Military Forces

Rashidun Caliphate

10,000–40,000 (modern estimates)

25,000–40,000 (primary sources)

Byzantine Empire

15,000–150,000 (modern estimates)

100,000–400,000 (primary Arab sources)

140,000 (primary Roman sources)

Casualties and losses

Rashidun Caliphate

1000 killed[2]

Byzantine Empire

45% or 50,000 killed (modern estimates)

70,000–120,000 killed (primary sources)

Background

Map detailing where the battle took place

After the death of the Islamic Prophet Muhammad in 632 CE, his closest confidant, Abu Bakr (r. 632-634 CE) assumed control over the community as the first Caliph of the Rashidun Caliphate (632-661 CE). Having taken the scepter, Abu Bakr faced an open rebellion from all corners of Arabia. Various tribes, who had bowed before the Prophet, declared that their covenant with Muhammad had ended with his life. These renegades were labeled as apostates and were confronted with the full might of Rashidun military in a series of engagements, later styled as the Ridda Wars (632-633 CE).

The most notable Rashidun military leader in this conflict was Khalid ibn al-Walid (l. 585-642 CE), a man cherished by Abu Bakr, despite his flaws, for his unparalleled talent in warfare. He had distinguished himself in warfare, earned the nickname of Saif Allah (the sword of God), and was easily one of the best strategists of his time. He proved to be instrumental in ensuring Rashidun victory against the rebels, all of whom were subdued within a year.

Abu Bakr then launched the expansion of his empire into Iraq and Syria. Khalid's division was sent to the former, where the caliphal army enjoyed much success under him, but the threat of a Byzantine counterattack on the Syrian divisions, who had gained considerable ground, prompted Abu Bakr to send Khalid there. Khalid crossed the barren and trackless desert with his best men, using camels as water reservoirs, and emerged on the fringes of Syria, where after some raiding and conquest, he confronted and defeated a major Byzantine force at Ajnadayn (634 CE)

Abu Bakr, in the meanwhile, died of natural causes and was replaced by Umar (r. 634-644 CE), who stripped Khalid of his command, either because of a personal grudge or because of his harsh personality. In his stead, Abu Ubaidah (l. 583-639 CE), a man renowned for his moral standards, was made the governor of Syria and the commander of the Rashidun corps stationed there. The Muslims continued to engulf the area, Damascus fell in 634 CE, the Byzantine garrison of Palestine was defeated in the battle of Fahl (Pella; 635 CE), and Emesa (Homs) fell in 636 CE, leaving Aleppo only a march away. The Byzantine emperor Heraclius (r. 610-641 CE), determined to rid his land of the Arabs, mustered up a huge force at Antioch to crush the invaders.

The Battle

Troop deployment.
  Muslim army (Red)
  Byzantine army(Blue)

Although Khalid was not officially in command, he was highly respected for his skill in battle, and Abu Ubaidah, who lacked such expertise, ceded the command to him. Initially, the Byzantines delayed their advance, wishing to strike simultaneously with the Sassanids whom they had allied with after decades of war. But the ruler of the Sassanian Empire, Yazdegerd III (r. 632-651 CE), required time to prepare, and the Byzantines, ever-impatient to drive the Arabs out, advanced on their own. Khalid, knowing that their position in the north was vulnerable, withdrew his forces all the way to the valley beyond the Yarmouk River. This plateau was an undulating flat land-mass, making it very suitable for the Arab light cavalry, which accounted for a quarter of his army's strength.

Negotiations dragged on for around three months, and during this time, the Rashidun army was reinforced from Medina. Not content with further delay, both sides prepared for combat. Vahan used his numerical superiority to fan out his frontline to about 13 kilometers, forcing the Muslim line to stretch thinner and cover a ground of 12 kilometers to face them. The Byzantine forces were placed in front of the Allan river, with their right anchoring the gorge to the south and their left bordering the Jabiya hills. Vahan arranged his forces as such:

1. Ghassanid light cavalry, under Jabalah, acted as the vanguard for screening and skirmishing
2. The left flank consisted of the Slavic infantry (facing the Muslim right)
3. Armenian infantry (under Vahan himself) and European contingents made up the center
4. Greek infantry manned the right flank (facing the Muslim left)
5. Cavalry divisions, mostly consisting of cataphracts - elite heavy mounted troops, were stationed behind each flank and the two central divisions

Khalid arrayed his 36 infantry regiments in a similar fashion, in front of the Harir River, with 3 light cavalry divisions positioned behind the line, and one larger cavalry reserve under his personal command in the rear. Unlike the multiethnic Byzantine forces, the Arabs were united not only in their nationalist sentiment but also by a common faith. In both armies, infantry consisted of melee fighters and skirmishers (such as archers), and although the Muslims lacked heavy troops, which abounded in the ranks of their foes, they made up for this loss with higher mobility and unparalleled skill in hand-to-hand combat.

On 15 August, fighting was initiated with several duels, as was the custom in the region, in which the Muslim champions appear to have bested their foes. Following this, Vahan ordered the advance of merely a third of his force to probe the Muslim lines for weaknesses; the fighting was not extreme and the Byzantines retreated after the day's end. Seeking to catch the Arabs by surprise, Vahan advanced at dawn on the following day, probably knowing that the Muslims would be busy offering their (Fajr) prayers. Khalid, however, had stationed scout patrols ahead of the main army in anticipation of such a surprise attack. The Byzantines, upon finding the Muslims completely alert, attacked anyway and locked their center in place as their flanks delivered the blows from either side. Muslim flanks, first the right and then the left, retreated to their camps, where, aided by their women, they managed to hold the enemy until relieved by Khalid's cavalry reserve.

The Byzantines continued to attempt to push through the Muslim ranks for the next two days, and just as Vahan's troops appeared to have made a breakthrough, Khalid would use his reserve to send them on the run. Seeking to buy some respite for his men, the Armenian field commander sued for peace on the fifth day. To the great shock of Abu Ubaidah, who was happily willing to comply, Khalid rejected the offer; the cunning general knew that the time to act was then. The fifth day ended without much fighting, and Khalid, knowing that his foes were demoralized, prepared an all-out assault for the next day, which had been his plan all along.

In the dark of the night, he sent a cavalry detachment around the field to take over the only bridge on the Wadi Ruqqad, cutting off the only escape route of the imperial army. The fighting started on 20 August 636 CE with another duel, where Abu Ubaidah got the best of his foe, a Greek commanding officer named Gregory, and then the entire Muslim line charged. As the infantry locked their kind on the opposing side in place, Khalid sprang into action and led a huge cavalry force, gathered from all of his cavalry divisions, around the Byzantine left flank. Vahan, realizing too late that he had been outwitted, failed to organize his disarrayed cavalry in time, and the Muslims smashed the Byzantine left into their center.

Surrounded on three fronts, and with no hope of assistance from the cataphracts, the imperial troops began to rout, but unbeknownst to them, their escape had already been cut off. Imperial troops were massacred in their retreat, and many drowned in the river, while some fell to their deaths from steep hills of the valley (many jumped to their deaths to avoid a melee with the Arabs). Khalid all but annihilated his foe and secured a crushing victory, whilst only taking around 4,000 casualties. Vahan either perished in the battle or, according to some, adopted a monastic lifestyle after the pulverizing defeat. Jabalah is said to have defected to the Rashidun side during the climax of the battle, and accepted Islam in 638 CE, only to apostatize later on and escape to Armenia.

Aftermath

With this stunning victory, the Muslims held uncontested power over the Levant and Syria. Jerusalem, a holy city for three monotheistic religions - Judaism, Christianity, and Islam - surrendered personally to the Caliph in 637 CE after receiving assurances of safety. Khalid ibn al-Walid, however, did not receive the prestige that was rightfully his. Umar officially discharged him of duty upon his visit to the region soon after the battle. Though Khalid's morals did not equal Umar's standards (there were some controversies against him), this action was much criticized, for it had been Khalid who saved the Muslim cause from certain doom, but Umar announced that he had done so to show the people that it was God alone who gave them victory.

Khalid retired peacefully (although he is said to have complained to Umar, saying that he was being treated like dirt), died in 642 CE, and was buried in Homs. Though he had been encouraged by many to rebel against Umar, Khalid refused to do so. The Muslims soon engulfed Egypt, parts of North Africa, and several islands in the Mediterranean. On the Sassanian front, a similarly spectacular victory at the Battle of al-Qadisiyya (636 CE) also opened up a similar channel of conquest, swelling the Islamic empire to a titanic size in a matter of mere decades.

Muslim success against these superpowers was due to a combination of reasons. Firstly, their maltreatment of the Syrian and Iraqis, respectively, inclined these people to not only welcome the new invaders but even assist them. Secondly, the years of fighting with each other had significantly weakened the two colossal empires. Thirdly, though the equipment of the Arabs did not parallel that of their foes, their skill in combat was unexcelled and the contributions of great generals like Khalid ibn al-Walid cannot be underestimated either.