An Utter Failure
Winter in Constantinople was as cold and bitter as anyone could remember. As tough as it was for the city’s defenders, at least the emperor had ensured there were enough supplies. The Muslims were used to warmer weather and the cruel winter resulted in the deaths of thousands. Snow remained on the ground for three months and their problems were exacerbated by serious delays in supplies arriving from Egypt. The invaders struggled on until spring when they hoped a new fleet and 50,000 troops from Egypt would turn the tide.
The 400 Muslim ships managed to sneak past the Byzantine fleet at night and sailed to the Hellespont. Their goal was to cut off supplies to the city but Leo had other ideas. His navy, aided by the desertion of Muslim sailors (who were actually Coptic Christians forced to work with the Arabs) launched a lightning attack in June 718 and once again, Greek Fire caused panic, confusion, and death amongst the enemy. The Christian sailors in the Muslim fleet that hadn’t already deserted, did so now and were welcomed by the Byzantines. After demolishing the Muslim blockade in the north of the city, Leo attacked the Arabs on the Asian side of the Sea of Marmara and won another crushing victory.
By now, the Arabs had no chance of forcing Constantinople to capitulate by sea so the rest of the fighting happened on land. Leo sent envoys to the Bulgars and Khan Tervel attacked the Muslims, handing them a devastating beating at the Battle of Adrianople. The Arabs lost over 20,000 men in the battle and it was clear that the siege was going to fail by that time. Umar decided to raise the siege when he heard rumors about a Frankish army that was riding to Constantinople to aid the Byzantines. Maslama led what remained of his army away from the city on August 15, 718. Once again, Constantinople proved to be too tough of a nut to crack; it wouldn’t be the last time.
Aftermath
Further disaster awaited the Arab invaders during their retreat as a storm destroyed the majority of the remaining ships. To say the Muslim siege of Constantinople was a complete catastrophe is putting it mildly. They lost an estimated 180,000 soldiers in total and all but five of their 2,000 ships made it home. If Maslama had succeeded in taking the city, Islamic forces would have had a relatively easy journey into central Europe. They would also have ruled European waters because no other nation had a navy to match them. Over 700 more years of Byzantine history would cease to exist and it’s fair to say that the world would have been a much different place.
The failure at Constantinople also severely weakened the power of the Umayyad Caliphate. It suffered massive losses in terms of manpower and finance. So much so in fact that Umar considered withdrawing his forces from recent conquests such as Transoxiana and Hispania along with evacuation of other territories. His advisors talked him out of these drastic measures but within 30 years, the Umayyad Caliphate was overstretched and the Abbasid Revolution (747 – 750) resulted in a power shift as the Umayyads lost their hold on the Islamic Empire.
Where Do We Get This Stuff? Here Are Our Sources
“Byzantium. The Surprising Life of a Medieval Empire.” Judith Herrin. 2007.