The siege of Damascus (634) lasted from 21 August to 19 September 634 before the city fell to the Rashidun Caliphate. Damascus was the first major city of the Eastern Roman Empire to fall in the Muslim conquest of Syria.
The last of the Roman–Persian Wars ended in 628, after Heraclius concluded a successful campaign against the Persians in Mesopotamia. At the same time, Muhammad united the Arabs under the banner of Islam. After his death in 632, Abu Bakr succeeded him as the first caliph. Suppressing several internal revolts, Abu Bakr sought to expand the empire beyond the confines of the Arabian Peninsula.
In April 634, Abu Bakr invaded the Byzantine Empire in the Levant and decisively defeated a Byzantine army at the Battle of Ajnadayn. The Muslim armies marched north and laid siege to Damascus. The city was taken after a bishop informed Khalid ibn al-Walid, the Muslim commander in chief, that it was possible to breach city walls by attacking a position only lightly defended at night. While Khalid entered the city by assault from the Eastern gate, Thomas, commander of the Byzantine garrison, negotiated a peaceful surrender at the Jabiyah gate with Abu Ubayda ibn al-Jarrah, Khalid's second in command. After the surrender of the city, the commanders disputed the terms of the peace agreement. The commanders finally agreed that the peace terms given by Abu Ubayda would be met. The peace terms included an assurance that no pursuit will be undertaken by Muslims against the departing Roman convoy for three days. Having acquiesced to the peace terms, it was three days after the surrender of the city that Khalid set out after the Damascan refugees towards Antioch and defeated them in battle six days later, near present day Al Jayyad.
Background
In 610, during the Byzantine–Sasanian War of 602–628, Heraclius became the emperor of the Byzantine Empire after overthrowing Phocas. While Heraclius focused his attention on the internal affairs of his empire, the Sassanid Persians conquered Mesopotamia, overran Syria in 611, and entered Anatolia to occupy Caesarea Mazaca. In 612, Heraclius expelled the Persians from Anatolia. In 613, he launched a counter offensive against Syria, but was decisively defeated.
Over the next decade, the Persians conquered Palestine and Egypt and Heraclius rebuilt his army, preparing for a new offensive, which he launched in 622. He achieved substantial victories over the Persians and their allies in the Caucasus and Armenia. In 627, he launched a daring winter offensive against Persia in Mesopotamia, and won a decisive victory at the Battle of Nineveh. This victory threatened the Persian capital city of Ctesiphon.
Discredited by this series of disasters, Khosrow II was killed in a coup led by his son Kavad II, who at once sued for peace, agreeing to withdraw from all occupied territories of the Byzantine empire. Heraclius restored the True Cross to Jerusalem with an elaborate ceremony in 629.
In Arabia, Muhammad had united most of Arabia under a single religious and political authority. When Muhammad died in June 632, Abu Bakr was elected to the newly formed office of Caliph, becoming Muhammad's political and religious successor as the first Rashidun caliph. Several Arabic tribes revolted against Abu Bakr. In the Ridda Wars, Abu Bakr quelled the revolt. By 633, Arabia was firmly united under the central authority of the Caliph in Medina. In 633, Abu Bakr initiated a war of conquest against the neighboring Sassanian and Byzantine empires. After a successful conquest of the Persian province of Iraq, Abu Bakr's confidence grew and in April 634 his armies invaded the Byzantine Levant from four different routes. These armies proved to be too small for the task, necessitating reinforcements from Iraq, led by Abu Bakr's capable general Khalid ibn al-Walid Crossing the desert, Khalid ibn al-Walid entered Syria from an unexpected route in a bold move. He attacked and overthrew the Byzantine defenses of Levant and quickly captured the Ghassanid capital city of Bosra. In July, the Muslim army under Khalid's command defeated another Byzantine army in the Battle of Ajnadayn. After clearing their southern flank, the Muslims laid siege to Damascus.
Siege site
Strategically located, Damascus attracted merchants from all over the world. The city was known as the paradise of Syria.
The fortifications matched its importance. The main part of the city was enclosed by a massive 11 m (36 ft) high wall.
The fortified city was approximately 1,500 m (4,900 ft) long and 800 m (2,600 ft) wide.
The wall had six gates:
Although the River Barada ran along the north wall of Damascas, it was too shallow to be of defensive importance. At the time of the Syrian campaign, the Byzantine Commander of Damascus was Thomas, son-in-law of Emperor Heraclius. A devout Christian, he was known for his courage and skill at command, and also for his intelligence and learning.
Dispositions
Without the necessary siege equipment, armies of the early Muslim expansion would surround a city, denying it supplies until the city's defenders surrendered. Meanwhile any chance of breaking into the city would be availed, if possible, using stealth and espionage. Muslim armies would usually isolate the city from the rest of the region and deploy scouts along vital routes.
Before the siege of Damascus, Khalid isolated it from the rest of the northern Syria. To the west, a detachment of cavalry at Fahal occupied the attention of the Byzantine garrison. This detachment also protected the Muslim supply lines to Medina. Thus this cavalry detachment functioned as the rearguard of the Muslim forces on the Syrian front. Another detachment was sent on the road to Emesa to take up a position near Bait Lihya, approximately 10 miles (16 km) from the city. Its instructions were to reconnoiter for any Byzantine relief columns. If unable to defeat or repel a Byzantine rescue effort, the detachment commander was instructed to send for reinforcements from Khalid.
Having isolated Damascus, Khalid ordered his army to surround the city on 21 August (the 20th of Jumada al-Akhira, 13 Hijri). The corps commanders were instructed to repel any Byzantine offensive from the respective gates and seek assistance in case of heavy attack. Dirar ibn al-Azwar commanded 2.000 horsemen from the mobile guard to patrol in the empty area between the gates at night and to reinforce any corps attacked by the Byzantines.
The following Muslim generals held the siege of the six gates of the Damascus. Each commander at the gate had 4,000–5,000 forces under his command:
Khalid placed the main body of his forces under the command of Rafi ibn Umayr at the eastern gate. He established his headquarters a short distance away from the eastern gate in a monastery, known since then as Deir al Khalid, the monastery of Khalid. Khalid's army had encircled the city, halting the flow of supplies into Damascus while the Ghouta of Damascus provided the Muslim army with all the supplies Khalid needed for his men and their mounts.
Byzantine relief
Emperor Heraclius was at Antioch at the beginning of the siege and on 9 September, he dispatched a relief force, thought to have numbered around 12,000 men. Scouts posted on the road from Emesa to Damascus reported the approach of a Byzantine army. Upon hearing this news, Khalid sent Rafi ibn Umayr with 5,000 troops. They met 20 miles (32 km) north of Damascus at Uqab Pass (Eagle Pass) on the Damascus-Emesa road. That force proved insufficient and was soon surrounded by the Byzantine troops. However before the Byzantines could defeat the Muslim detachment, Khalid arrived with another column of 4,000 men and routed them. It has since come to be known as Battle of the pass of Uqab.
The Muslim siege forces had been weakened by the withdrawal of 9,000 men to repel the Byzantine relief force. If the Byzantine garrison had sallied out against the Muslim army, historians suspect the defenders would have broken through the Muslim lines and lifted the siege. Understanding the danger of the situation, Khalid hurriedly returned to Damascus.
First Byzantine attack
After realizing that no reinforcements would come, Thomas decided to launch a counter offensive. Early in the third week of September, Thomas drew men from all sectors of the city to form a force strong enough to break through the Gate of Thomas. He was there faced by Shurahbil with his corps of about 5,000 men. The Byzantine attack began with a concentrated shower of arrows against the Muslims. The Byzantine infantry, covered by the archers on the wall, rushed through the gate and fanned out into battle formation. Thomas himself led the assault. During this action, Thomas was struck in his right eye by an arrow. Unsuccessful in breaking the Muslim lines, the Byzantines retreated back to the fortress. The wounded Thomas is said to have sworn to take a thousand eyes in return. He ordered another great sortie for that night.
Second Byzantine attack
This time Thomas planned to launch simultaneous sorties from four gates. The main sector was to be again the Thomas gate, to take full advantage of the exhausted Muslim corps stationed there. The attacks from the other gates—Jabiya Gate, the Small Gate and the Eastern Gate—were intended to tie down the other Muslim corps so that they could not aid Shurhabil's corps at the Thomas gate.
At the Eastern Gate, Thomas assembled more forces than at the other gates, so that Khalid would be unable to move to Shurahbil's assistance and take command in that decisive sector. Thomas' attack at several gates also gave more flexibility to the operation: if success were achieved in any sector other than the Gate of Thomas, such success could be exploited by sending troops to that sector to achieve the breakthrough. Thomas ordered Khalid to be taken alive.
After some hard fighting at the Jabiya Gate, commander Abu Ubayda and his men repulsed the sally and the Byzantines hastened back to the city. The battle was intense at the Small Gate, which was guarded by commander Yazid and his men. Yazid had fewer troops but Dharar came to Yazid's aid with his 2,000 cavalry of the Mobile Guard. The cavalry attacked the flank of the Byzantine sortie force and repulsed the sally.
At the East Gate, the situation also became serious, for a larger Byzantine force had been assigned to this sector. Rafay was unable to withstand their attacks. The timely arrival of Khalid with his reserve of 400 veteran cavalry and his subsequent attack on the Roman flank marked the turning point in the sally at the Eastern Gate.
The heaviest fighting occurred at the Thomas gate, where Thomas again commanded the sally in person. After intense fighting, Thomas, seeing that there was no weakening in the Muslim front, decided that continuing the attack would be fruitless and would lead to even heavier casualties among his men. He ordered a withdrawal and the Romans moved back at a steady pace, during which they were subjected to a concentrated shower of arrows by the Muslims. This was the last attempt by Thomas to break the siege. The attempt had failed. He had lost thousands of men in these sallies, and could no longer afford to fight outside the walls of the city.
Khalid's attack
On 18 September, a priest named Jonah informed Khalid about a festival celebration in the city that night. The festivities offered Khalid an opportunity to capture the city in a surprise attack on the relatively lightly defended walls. In return, Jonah requested immunity for himself and his fiance. According to Muslim chronicles, she was still not handed over to him because of the arrival of the Muslim army that was to besiege Damascus, and according to the narrations he came to Khalid with this information only to get his wife sooner. Jonah also converted to Islam.
With no time to make a coordinated plan of attack for the whole army, Khalid decided to storm the East Gate himself. He, Qa'qa ibn Amr, and Mazur ibn Adi climbed the wall hand-by-hand from the side of the gate. This part of the wall was the strongest, no guard was stationed at the top. They secured ropes to the wall and dropped them to 100 selected soldiers waiting at the base. Leaving a few men to assist the climbers, Khalid descended into the city, killing the guards at the inside of the East Gate. Khalid and Qa'qa flung the gate open and the remainder of Khalid's men entered the city. An intense battle ensued.
When Thomas saw that the rest of the army did not move from the other gates, he assumed first that only Khalid's army had entered the city and second that the other corps commanders were unaware of the breach in the defenses. Thomas tried to save Damascus for one last time. He sent envoys to the Jabiya Gate to talk with Abu Ubayda , the second in command to Khalid, and offered to surrender the fort peacefully and to pay the Jizya. Abu Ubayda, who was well known for his peace-loving nature, accepted the terms, thinking that Khalid would also agree.