Dedicated to the military history and civilization of the Eastern Roman Empire (330 to 1453)

"Time in its irresistible and ceaseless flow carries along on its flood all created things and drowns them in the depths of obscurity."

- - - - Princess Anna Comnena (1083–1153) - Byzantine historian

Tuesday, October 4, 2011

The Siege of Constantinople

Artist conception of Arab forces that could have faced Roman troops.

The First Arab Siege of Constantinople (674 - 678) 

The first Arab siege of Constantinople is perhaps the single most important military action in the history of Western Civilization.  But it is a battle that little is known about.

The Umayyad Caliphate was fresh with a sting of victories and backed by the fervor of the new religion of Islam.  The "nations" of the West were basically non-existent.  If Constantinople had fallen at this point there would have been nothing to stand in the way of an Arab sweep up through the Balkans into central Europe.


In the 7th Century the Eastern Roman Empire was under enormous military pressure on multiple fronts for decade after decade.  For the Romans, the 7th Century was almost non-stop war, invasions, counter invasions, amphibious operations, battles, sieges and sea battles.

The Empire was attacked by a series of enemies  -  Persians, Slavs and Arabs.  In the last of the Roman-Persian Wars (602 - 629 AD) the Empire had almost ceased to exist.  The great Roman Emperor Heraclius totally crushed the Persians reducing them to a state of internal anarchy and restored the Eastern Empire.

Roman Emperor Constantine IV and his court.  He organized the military and city of Constantinople for a siege of five years while fighting wars on multiple fronts over three continents (Africa, Europe and Asia).

The Arab Invasions 

After the near death war with Persia the Empire badly needed peace, but that was not to be.  Islam now exploded on to the Middle East.  In late 620s Muhammad had already managed to conquer and unify much of Arabia under Muslim rule.

Starting in the 630s Arab armies fought an almost endless series of major engagements with Eastern Roman forces.  The slower moving and traditional Byzantine armies fought a losing battle against light and nimble Arab cavalry forces that out maneuvered them in the open country and deserts.  The results of the battles was the loss long held Roman provinces of Egypt, Cyrenaica, Arabia, Palestine, Mesopotamia, Armenia and Syria.

The pressure facing the Romans was not just military.  With every lost province the Empire was losing its tax base, food supplies, business income and population.  Areas that once supplied the Empire with bureaucrats, educators, soldiers, religious leaders and businessmen were now under the control of the Arab invaders.

VIDEO:  The Byzantine Army

The Late Roman Army

Constans II was the last Emperor to campaign in northern Italy and visit Rome as an Imperial possession.  He was also the last to exert real control over the Popes, arresting Martin I (649-653, d.655) and exiling him to the Crimea.

Under Constans the structure of the Roman Army was fundamentally changed to deal with the new circumstances of the Empire. As the traditional units, largely familiar from the 5th Century, fell back from the collapsing frontiers, they were settled on the land in Anatolia, to be paid directly from local revenues instead of from the Treasury, whose tax base from Syria and Egypt had disappeared.

The areas set aside for particular units became the themes, which remained the military bedrock of Romania until the end of the 11th century and soon replaced the old Roman provinces as the administrative divisions of the Empire.

Byzantine infantry re-enactor.

The Army of the East, driven out of Syria, was settled in the Anatolic Theme, where it would guard the obvious route for invasion or raids from Syria: the Cilician Gates through the Taurus Mountains. Although invasions and raids there would be, the Arabs never did secure any conquests beyond the Gates. Where the Army of the East in the Late Empire numbered about 20,000 men, the forces of the Anatolic Theme varied from about 18,000 in 773 to 15,000 in 899 [Warren Treadgold, Byzantium and Its Army, 284-1081, Stanford, 1995, p.67].

As the remnants of the Late Roman Army were settled on the land, there were also standing forces that accompanied the Emperor. There was already one such unit in the Late Empire, the Scholae. This would grow into a new Standing or Mobile Army, the Tagmata.  The Tagmata together numbered about 28,000 men, while the entire Army, Themes and Tagmata combined, added up to about 128,000 men [Treadgold, op.cit.].

This was less than half of the Augustan Army and not even a quarter of Constantine's; but considering that the Empire is reduced to the lower Balkans and Anatolia, it is proportionally still robust, especially in an Age when a paid military establishment was impossible in most of Europe.

Despite this unprecedented disasters and loss of territories, the internal structures of the army remained much the same, and there is a remarkable continuity in tactics and doctrine between the 6th and 11th centuries.

Roman Empire military districts in 668AD.  The Empire had to defend North Africa, Italy
the Balkans and Asia Minor.
Click graphic to enlarge.

Three of the four sides of the city of Constantinople were the ocean.  Here are the sea walls of the city.
Only a small number of enemy troops could land at one time, and they would be vulnerable to Byzantine
attack with arrows, boiling oil, rocks etc.

Opening Moves

In spring 669, after receiving additional troops, Arab forces entered Asia Minor and advanced as far as Chalcedon, on the Asian shore of the Bosporus across from the Byzantine capital, Constantinople. The Arab attacks on Chalcedon were repelled, and the Arab army was decimated by famine and disease. Mu'awiya dispatched another army, led by his son (and future Caliph) Yazid, to Fadhala's aid. Accounts of what followed differ.

The Byzantine chronicler Theophanes the Confessor reports that the Arabs remained before Chalcedon for a while before returning to Syria, and that on their way they captured and garrisoned Amorium. This was the first time the Arabs tried to hold a captured fortress in the interior of Asia Minor beyond the campaigning season, and probably meant that the Arabs intended to return next year and use the town as their base, but Amorium was retaken by the Byzantines during the subsequent winter.

The campaign of 669 clearly demonstrated to the Arabs the possibility of a direct strike at Constantinople, as well as the necessity of having a supply base in the region. This was found in the peninsula of Cyzicus on the southern shore of the Sea of Marmara, where a raiding fleet under Fadhala ibn 'Ubayd wintered in 670 or 671.

Re-enactor preparing to imitate Roman-Byzantine
infantryman from the age Justinian.  The Roman
infantry at the time of the siege could have looked
much like this soldier.

Mu'awiya now began preparing his final assault on the Byzantine capital. In contrast to Yazid's expedition, Mu'awiya intended to take a coastal route to Constantinople. The undertaking was not haphazard, but followed a careful, phased approach: first the Muslims had to secure strongpoints and bases along the coast, and then, with Cyzicus as a base, Constantinople would be blockaded by land and sea and cut off from its agrarian hinterland, on which it depended for its food supply.

Accordingly, in 672 three great Muslim fleets were dispatched to secure the sea lanes and establish bases between Syria and the Aegean. Muhammad ibn Abdallah's fleet wintered at Smyrna, a fleet under a certain Qays wintered in Lycia and Cilicia, and a third fleet, under Khalid, joined them later. According to the report of Theophanes, the Emperor Constantine IV, upon learning of the Arab fleets' approach, began equipping his own fleet for war.

Constantine's armament included siphon-bearing ships intended for the deployment of a newly developed incendiary substance, Greek fire. In 673, another Arab fleet, under Gunada ibn Abu Umayya, captured Tarsus in Cilicia, as well as Rhodes. The latter, located midway between Syria and Constantinople, was converted into a forward supply base and centre for Muslim naval raids. Its garrison of 12,000 men was regularly rotated back to Syria, a small fleet was attached to it for defence and raiding, and the Arabs even sowed wheat and brought along animals to graze on the island.

The Byzantines attempted to obstruct the Arab plans with a naval attack on Egypt, but it was unsuccessful. Throughout this period, overland raids into Asia Minor continued, and the Arab troops wintered on Byzantine soil

Siege of Constantinople

The five year siege of this great city was the most important battle in the history of the Western world.  If the Arab armies had broken the Romans at Constantinople nothing would have stood in their path to invade Europe.

We know so very, very little about this battle.  But what we can do is use the information we do have to extrapolate what might have happen based on military history in general.

Many historians in the last few centuries have taken their cue from Edward Gibbon in his Decline and Fall of the Roman Empire.  Gibbon would often look down on the Byzantines as pretend Romans.  He would long for the good old days of the Legion.

Gibbon savagely attacked "the courage and vigilance of the reigning emperor, who disgraced the name of Constantine."  Gibbon's insults are not real history.  The Emperor Constantine IV organized the Empire for multiple major military operations at the same time including the great siege of the capital itself.  That implies a major degree of planning, command and control with a large professional military and civil service.

Byzantine Infantry

Multi-Front Warfare:  There was active warfare in North Africa with Arab invasions slowly taking over Roman provinces.  The Slavs were (as usual) yet again invading the Balkan provinces.  Arab armies had just conquered Roman Armenia and threatened the rest of Asia Minor.  More Arab armies were in Syria pinning down Roman units and pushing up the coast of Anatolia.  And now a massive naval invasion force is heading to Constantinople itself.

To say that Constantine IV had his hands full is an understatement.

Troop Deployment:   The Byzantine historian Treadgold says the strength of the Roman Army at this point was 109,000 men under arms.  We cannot be sure how many troops were assigned to Constantinople for the coming siege.  What we can do is to work backwards from the 109,000 number and subtract units that appear to have been assigned to other areas.  (see map graphic above.)

  • 15,000 troops.  Army of Africa, Exarchate of Africa.
  • 20,000 troops.  Army of Italy, Exarchate of Ravenna.
  • 20,000 troops.  Army of the East, Anatolic Theme.
  • 15,000 troops.  Army of Armenia, Aramenic Theme.

These units total 70,000 men more or less, but it is all guess work.  The important point is these units are based far from Constantinople itself and cannot be easily or rapidly re-deployed to other areas.  If troops were taken from the Army of the East then that part of the frontier would be weakened in the face of enemy forces and invite invasion on yet another front.

So it might be safe to say that in the greater Constantinople area the Emperor might have available to him in the range of 39,000 troops.  Perhaps more men might have been available through raising additional civilian militias and volunteer units.  But a certain number of these troops would have to be pealed away from defending Constantinople in order to defend other cities and strategic points in the area.

For example, when the siege of Constantinople was raised Constantine rushed to go to the relief of Thessalonika, which was still under siege from the Slavs.  So some units must have been assigned garrison duty in the Balkans. 

But a Slavic siege going on at the same time as an Arab siege makes you wonder if there was co-ordinated action between Arab and Slav forces.  Maybe the Slavs were just taking advantage of the situation.  Recorded history is silent on a possible alliance.
7th Century Arab Soldier

I can find no real information on the numbers of Arab troops transported to the area for the siege.  If you look at military history in general those conducting a siege usually outnumber those inside the walls to a large degree.  If not then those inside could easily break out or bring in supplies. 

If the Romans had 25,000 plus troops inside the city it is fair to say the Arabs would not have shown up with less.  I would give the Arabs a force of 40,000 or more troops as the minimum needed to maintain a siege.  In the 2nd siege carried out 40 years later the Arabs had 80,000 or more men.  So it is possible that the 40,000 estimate for the 1st siege is too low.

Romans    -    25,000 or more
Arabs       -    40,000 maybe much higher

Naval Forces  -  There are no numbers on the Arabs ships.  The Romans used over 1,100 ships to transport a large invasion force of tens of thousands of troops and their supplies in the attack on Carthage in 468 AD.  It is reasonable to think that the Arabs might use a fleet of about the same size or less.

The Romans had almost their entire fleet crushed in 655 in "The Battle of the Masts."  With so many provinces lost and constant wars, the money available for national defense would have been tight.  What fleet the Romans had available they kept close to the city.

Theodosian Land Walls, Belgrade Gate/Second Military Gate/Xylokerkos Gate.

The Battle Begins

In 674, the Arabs launched the long awaited siege of Constantinople.  The great fleet that had been assembled set sail under the command of Abd ar-Rahman before the end of the year; and during the winter months some of the ships anchored at Smyrna, the rest off the coast of Cilicia.  Additional squadrons reinforced the forces of Abd ar-Rahman before moving on.  The naval forces of the Umayyads passed through the unguarded channel of the Hellespont about April 674.

But the besiegers had formed an insufficient estimate of the strength and resources of Constantinople.  Simply the Arabs had no idea what they were going to face.  The size of Constantinople and its massive defenses had shocked visitors for centuries on end.

Now a perhaps fairly lightly armed Arab army and fleet would have shown up with no idea on how to break into this fortress defended by a system of multiple walls and the ocean itself.

The Arabian fleet cast anchor, and the troops were disembarked near the palace of Hebdomon, seven miles from the city. From the first light of dawn till the evening over a period of many days the Arab infantry attacked the city's land walls from the Golden Gate going far to the east.  The reports say that the warriors in front were pushed forward toward the walls by the weight of the troops piling up behind them.

The solid and lofty walls were guarded by numbers and discipline: the spirit of the Romans was rekindled by the last danger to their religion and empire. The fugitives from the conquered provinces more successfully defended the city than they had at the sieges of Damascus and Alexandria. 

VIDEO:  Greek Fire

Greek Fire:  Just prior to the siege, a Syrian Christian refugee named Kallinikos (Callinicus) of Heliopolis had invented for the Byzantine Empire a devastating new weapon that came to be known as "Greek fire".   Its ingredients are a much debated topic, with proposals including naphtha, quicklime, sulphur, and niter. What set the Byzantine usage of incendiary mixtures apart was their use of pressurized siphons to project the liquid onto the enemy.

The first reports of the use of Greek Fire appears to have been on the Arab infantry trying to break through the land walls.  It is said they "were dismayed by the strange and prodigious effects of artificial fire."

This firm and effectual resistance by the Romans discouraged the Arab forces that were used to quick victories with fast moving cavalry tactics.  Arab soldiers came looking for fast loot and slaves.  The Arab leadership needed to keep the troops happy.  They diverted their arms to the more easy attempt of plundering the European and Asiatic coasts of the Propontis. 

Greek Fire

After controlling the sea from the month of April to that of September, on the approach of winter they retreated eighty miles from Constantinople, to Cyzicus, in which they had established their magazine of spoil and provisions.

For the six following summers the Arabs repeated this same pattern of attack and then retreat for the winter months. 

Then in 677 after three years of siege, the Byzantine navy utilized Greek Fire to decisively defeat the Umayyad navy in the Sea of Marmara.  The naval victory that the Byzantines won ensured that the city could be re-supplied by sea.  Meanwhile, the Arab forces were beset with starvation in winter.

Each year had seen a gradual abatement of Arab hope and vigor.  Finally after years of naval defeats and a fruitless siege the Arab forces broke camp in 678 and returned home.

It was said that 30,000 Arabs had died.  Byzantine casualties were thought to be several thousand.


The victory for the Romans was total.

As the Arabs withdrew from Constantinople they were almost simultaneously defeated by the Romans on land in Lycia in Anatolia.

Byzantine historian J.B. Bury says the Arab fleet was caught in a storm and dashed on the rocks off the southern coast of Turkey near modern day Antalya.  What was left of the Arab fleet was destroyed by a Roman fleet operating from the Byzantine Theme of Cibyraiot off the southern coast of Asia minor.

In addition the Muslims of Syria came under attack by Christian irregular troops or armatoli operating in the Taurus Mountains.  The armatoli attacked and plundered Muslims from Asia Minor all the way south to Mount Lebanon.  Reinforced by Christian Syrians and Slavs they grew in power raiding as far as Jerusalem and helping Christian refugees escape to the north away from Islam.    

These losses at Constantinople, of the fleet and setbacks on land forced the Umayyads to seek a truce with Constantine.  The Roman Ambassador was received in Damascus by a general council of emirs.  A peace of thirty years was signed.   The Arabs evacuated the islands that they had captured in the Aegean.  In addition they paid the Romans an annual tribute consisting of fifty slaves, fifty horses and 3,000 pounds of gold. 

With the siege raised, Constantine could march to the relief of Thessalonika which was under siege from the Slavs.

The Arab invasions has finally been checked by Roman arms.  Europe was saved from an invasion they had no way to counter.

One artist's view of Greek Fire being used by the Byzantines.

The horror of burning to death by Greek Fire would have given the Byzantines a huge edge in battle.

Two maps showing the Eastern Roman Empire.  Top map shows the Empire after the defeat of
the Persian Empire.  The bottom map shows the Arab conquest of Egypt, Syria and Palestine.
Click on map to enlarge.

Constantinople in the Byzantine period.
Click image for full size map.

The Decline and Fall of the Roman Empire, Gibbons


Anonymous said...

Certainly, someone, by now has informed you that you have a picture of Rumeli Hisar, built by the Turks in preparation for the siege of 1453 and naming it as the sea walls of Byzantium. A very distinctive fortress, Rumeli is on the European side and Anadolu fortress is on the Asian or "Anatolian" side. Together they had control of the passage.

Gary said...

Congratulations. You are the first.

This is a three year old article. Sometimes I do these in the dead of night when the mind is nearly gone. I will try to get around to a correction with a new correct photo.

One of the things that drives me crazy is other sites putting incorrect labels on photos or paintings etc. I have chosen not to use any number of photos because I can't figure out what it is a photo of. You will have 3 sites each with a different caption.


Anonymous said...

Please keep up the good work, which is obviously a labour of love. When people 'help' you with their knowledge continue to thanks them. And, although I would not have voted for Trump, I salute his victory

Unknown said...

Hi Gary. This article is fascinating. Came across it whilst looking for info about the Second Siege of Constantinople in 717-718. Do you have a similar article on that conflict? Would love to read it if you do. Regards. Theo.

Gary said...

Working on it.

Unknown said...

Fancy a conversation?! I'm plotting out a novel which (perhaps rashly) drives towards the 717/718 siege as its climax. I'm digging around for more material and would be very interested to draw on your wisdom and expertise in this area. If you can spare time to connect my email is theobrun@gmail.com Thanks.