Battle of Volturnus - Romans vs Franks

Franks vs Romans at the Battle of Volturnus.
The Franks generally fought naked to the waist, with leather trousers, without breastplate or greaves, and bareheaded, though a few had helmets.  The Franks were armed with lance, sword and ax.

Franks vs Romans in 554 AD . . . . the last stages of the Gothic Wars



The Battle of the Volturnus, also known as the Battle of Casilinum or Battle of Capua, was fought in Central Italy in 554 between an army of the Eastern Roman Empire and a combined force of Franks and Alemanni. The Romans, led by Narses, were victorious.

Background

During the later stages of the Gothic War, the Gothic king Teia called upon the Franks for help against the Roman armies under the eunuch Narses. 


Although king Theodebald refused to send aid, he allowed two of his subjects, the Alamanni chieftains Leutharis and Buccelin, to cross into Italy. According to the historian Agathias, the two brothers gathered a host of 75,000 Franks and Alamanni, and in early 553 crossed the Alps and took the town of Parma. They defeated a force under the Heruli commander Fulcaris, and soon many Goths from northern Italy joined their forces. In the meantime, Narses dispersed his troops to garrisons throughout central Italy, and himself wintered at Rome.   

Narses spent the winter in Rome, and in the spring (A.D. 554) his army, which had been dispersed among the forts and towns in the Ravennate region for the winter, was collected and reunited at Rome. We do not know his reasons for this retreat, which meant the abandonment of Etruria and the Hadriatic provinces to the enemy. He could rely with some confidence on his garrisons in the great fortresses, but the open country and unwalled towns were at the mercy of the invader.

The host of Buccelin and Leutharis moved southward, without haste, plundering and destroying. When they approached Rome they divided into two separate armies, of which the larger under Buccelin, avoiding Rome itself, marched through Campania, Lucania, and Bruttii to the Straits of Messina, while Leutharis led the other through Apulia and Calabria as far as Hydruntum. The provinces were systematically plundered, and an enormous booty was collected. In this work of pillage and devastation there was a marked difference between the conduct of the Franks and their Alamannic comrades. The Franks, who were orthodox Christians, showed respect for churches, but the heathen Alamanni were restrained by no scruples from carrying off the ecclesiastical plate and pulling down the roofs of the sacred buildings.

When he had reached the limits of Calabria, Leutharis laden with spoils decided to return home to enjoy them. He had no political ambitions, and his one thought was to get safely away with his wealth and run no further risks. He marched along the coast as far as Fanum, but there his troops suffered considerable losses through an attack by the Roman garrison of Pisaurum, and the greater part of the booty was lost. Leaving the coast he struck into the Apennines and reached the Po safe but dispirited. At the Venetian town of Ceneta, where he took up his quarters to rest, a virulent plague broke out in the army and Leutharis himself was one of its victims.

18,000 Romans vs 25,000 to 30,000 Franks.
General Narses deployed the Roman cavalry on each wing anchored by the forests and placed his infantry in the center, but it was not a solid center.  There was a gap where the Roman allied Herul troops should have been.  The army of the Franks consisted entirely of infantry.  They formed an infantry wedge and marched directly for the gap in the center of the Roman lines.   

The Battle

Buccelin returned to Campania and encamped on the banks of the Vulturnus close to Casilinum and Capua, which are only a few miles apart.  Casilinum is the modern Capua, and the ancient Capua is the modern village of S. Maria di Capua Vetere. On one side the river formed the wall of his camp, on the other side he fortified it securely. He had some hopes that he would soon be reinforced, for his brother had promised that when he had reached Venetia he would send back his troops. 
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As soon as Narses learned that Buccelin had occupied this position at Capua he marched from Rome with his army, numbering about 18,000, and encamped not far from the enemy. The battle which ensued was probably fought across the Appian Way which passed through Capua and crossed the river at Casilinum.

The course of the battle was affected by an accident. One of the Herul captains killed his servant for some delinquency, and when Narses called him to account asserted that masters had the power of life and death over their slaves and that he would do the same thing again. He was put to death by the command of Narses, to the great indignation of the Heruls, who withdrew from the camp and said they would not fight. Narses drew up his line of battle without them. He placed his cavalry on the two wings and all the infantry in the centre. 

Byzantine Armored Cavalry.
Trained to fire the bow on horseback, they could do enormous damage to an enemy from afar and then close in for the kill with lance and sword.

There was a wood on the left, and Valerian and Artabanes, who commanded on that side, were directed to keep a part of their forces concealed in the wood till the enemy attacked. Narses himself commanded on the right. The leader of the Heruls, Sindual, who was burning to fight, implored Narses to wait until he could persuade his followers to reserve a place for them, where they could fall in, if they arrived late. Accordingly he left an open space in the middle of the infantry.

Meanwhile two Heruls had deserted to the enemy, and persuaded Buccelin that his chance was to attack at once, as the Romans were in consternation at the defection of the Herul troops. Buccelin had drawn up his army, which consisted entirely of infantry, in the shape of a deep column, which should penetrate like a wedge through the hostile lines.  

6th Century Eastern Roman infantry.

In this array the Franks arrived, armed with missile lances, swords, and axes, confident that they would sweep all before them at the first rush. They penetrated into the central space which was to have been occupied by the Heruls, dislodging the outer ranks of the Roman infantry on either side. Narses quietly issued orders to his wings to face about, and the enemy were caught between the cross fire of the cavalry, who were all armed with bows. 

The Franks were now facing both ways. The archers on the right wing aimed at the backs of those who were fighting with the infantry on the left, the archers on the left wing at the backs of those who were engaged with the right. The barbarians did not understand what was happening. They saw the foemen just in front of them with whom they were fighting hand to hand, but they could not see the enemies who from far behind were raining arrows upon their backs. Their ranks were gradually mown down, and then Sindual and his Heruls appeared upon the scene. 

The defeat of the Franks was already certain; it was now to be annihilation. Buccelin was slain and only a handful escaped alive from the stricken field. The Roman losses were small. It will be noticed that Narses won this, his third victory, by a tactical plan similar to that which he had employed in the battle with Totila.


Perhaps 80 Romans were killed.  It was reported that only five Franks escaped.

With the Franks totally engaged in the center, Narses ordered his cavalry on the right and left flanks to close in.  The Franks were caught in a crossfire and their army annihilated.  

Aftermath


The Italians had been terror-stricken by the ruthless deeds of the northern barbarians, and they were wild with joy at the news of their utter destruction. Narses and thoughtful people had little hope that the brilliant victory of Capua head dispelled the danger. They reflected that the foes whose corpses were strewn on the banks or floated in the waters of the Vulturnus were such a small fraction of the Frank people and their dependents, that their fate would provoke rather than intimidate. They expected that a greater host would soon come down to avenge the fallen and restore German prestige. 

These fears were not realized, as they might well have been if Theodebert had been still alive; his feeble son Theodebald, who suffered from a congenital disease, died in the following year. Narses was able to complete in peace the settlement of Italy.

The winter months which followed the battle of Capua were spent in besieging Capsa, a strong place in the Apennines, where seven thousand Goths had established themselves under the leadership Ragnaris, the man who had behaved so treacherously at Tarentum. Campsa has been identified with Conza, about fifty miles east of Naples. Its position defied assault and Narses sat down to blockade it, but a large stock of provisions had been laid in. 

At the beginning of spring (A.D. 555), Ragnaris proposed to Narses that they should meet and discuss terms. Narses refused to agree to his proposals, and he retired in great wrath. When he was near the wall of the fort he turned round, drew his bow, and aimed an arrow at the general who was returning to his lines. It missed its mark, but one of the guardsmen who were with Narses had a surer aim, and transfixed the treacherous Goth. He fell dead, and the garrison surrendered immediately and were sent to Constantinople.

All Italy south of the Po was now restored to the Imperial authority. Of the subjugation of the Transpadane provinces, where Goths and Franks were still in possession, we have no record. It was a slow business, and Verona and Brixia were not recovered till A.D. 562. In November of that year Narses sent the keys of their gates to Justinian.

History of the Later Roman Empire by J. B. Bury (1923)

(Wikipedia)

6th century Frankish infantryman.

The Gothic Wars resulted in the Eastern Roman Empire re-conquering the areas of modern

Italy and Dalmatia.

The Second Battle of Marcellae

Medieval Bulgarian warriors. 
Khan Asparuh crosses the Danube in 680 AD. 

The Second Battle of Marcellae (792 AD)

• “The Bulgarians are a huge, mighty and warlike people that have subdued all their neighboring nations. One horseman of theirs can face 100 or 200 horsemen of the infidels. When they go to war they form lines – in front are the archers with their bows, and behind are the women and children…”
  Abu al-Hassan Ali ibn Hussein ibn Ali al-Massoudi, 10th Century AD

The greatest enemies of the Eastern Roman Empire were the Arabs, the Turks and the Bulgarians.  This article deals with the early invasion and establishment of the Bulgarian Empire on Roman soil directly up against Constantinople itself. 
                                                                    .
The Romans and Bulgarians clashed at the Second Battle of Marcellae.   It took place in 792 at Markeli, near the modern town of Karnobat in south eastern Bulgaria. It is not to be confused with the earlier battle at the same place.
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In the last quarter of the 8th century Bulgaria overcame the internal political crisis after the end of the rule of the Dulo. The khans Telerig and Kardam managed to consolidate the central authority and put an end of the quarrels among the nobility.

Roman Emperor Constantine VI (right of the cross) presiding over
the Second Council of Nicaea. 

The Bulgarians finally had the opportunity to intensify their campaigns in Macedonia and annex the region and its Slavic population to their state. In 789 they penetrated deep into the valley of the Struma river and heavily defeated the Byzantines, killing the strategos of Thrace Filites. 
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In order to distract the Bulgarian attention from Macedonia, the Byzantine emperor Constantine VI started a campaign in northern Thrace in April 791. The armies met near the fortress of Provat (20 km east of Odrin) and the Byzantines were forced to retreat but their defeat was not decisive and in the following year the campaign was renewed.
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Forces Involved


It is maddening for a historian to try and deal with so many of the Byzantine wars because there is so very little information on events that were often of major importance.  In the Battle of Marcellae there is next to no information.  So one must speculate. 
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ROMANS   -   At the head of his troops, the Emperor himself was marching directly into enemy held and fortified territory.  It is fair to say that all available troops would be with the Emperor and this would be considered a major campaign.
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Historians speculate that the Roman army would have numbered in the 80,000 to 90,000 range at this point.  Most of the forces would be stationed along the frontiers facing the Arabs or Persia.  Other troops would be in Greece, Italy, the Crimea and Balkan frontier posts.  The Emperor might head an invading army of perhaps 15,000 to 20,000 men.  That number was often considered a standard size for major operations.
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The Roman force would have been a combination of infantry and cavalry units near Constantinople.  The full-time units were the tagmata.  They were the professional standing army of the Empire.

Eastern Roman Infantry

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The tagmata were exclusively heavy cavalry units and formed the core of the imperial army on campaign, augmented by the provincial levies of thematic troops who were more concerned with local defense.


BULGARIANS   -   There is no way to know numbers, but it is very likely the Bulgarians would have fielded a force perhaps equal to the Romans.
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The army consisted of a Bulgar cavalry and a Slavic infantry. The core of the Bulgarian army was the heavy cavalry, which consisted of 12,000–30,000 heavily armed riders. At its height in the 9th and 10th centuries, it was one of the most formidable military forces in Europe and was feared by its enemies. There are several documented cases of Byzantine commanders abandoning an invasion because of a reluctance to confront the Bulgarian army on its home territory.
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The Bulgars were well versed in the use of stratagems. They often held a strong cavalry unit in reserve, which would attack the enemy at an opportune moment. They also sometimes concentrated their free horses behind their battle formation to avoid surprise attacks from the rear.They used ambushes and feigned retreats, during which they rode with their backs to the horse, firing clouds of arrows on the enemy. If the enemy pursued disorganized, they would turn back and fiercely attack them.
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The Bulgarian army was well armed according to the Avar model: the soldiers had asabre or a sword, a long spear and a bow with an arrow-quiver on the back. On the saddle they hung a round shield, a mace and a lasso, which the Bulgarians calledarkani. On their decorated belts the soldiers carried the most necessary objects such as flints and steel, a knife, a cup and a needle case. The heavy cavalry was supplied with metal armour and helmets. The horses were also armoured. Armour was of two types — chain-mail and plate armour. The commanders had belts with golden or silver buckles which corresponded to their rank and title.
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The infantry of the newly formed state was composed mainly of Slavs, who were generally lightly armed soldiers, although their chieftains usually had small cavalry retinues. The Slavic footmen were equipped with swords, spears, bows and wooden or leather shields. However, they were less disciplined and less effective than the Bulgar cavalry.


VIDEO  -  Troops of Eastern Roman Empire-681 AD.  This clip is from a Bulgarian Movie made in 1981.  No CG or special effects are used.  These are real people marching.  It helps bring alive what it must have been like to see a Byzantine army on the march.

The Battle
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In the summer of 792 Constantine VI led his army north and on 20 July was confronted by the Bulgarians under Khan Kardam near the border castle Marcelae. 
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The Khan had built ramparts blocking the roads to the Rish Pass and the capital Pliska.  Rather than seeking out the Roman army the Khan awaited an attack in his fortified positions.
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For several days the emperor did not dare to attack but by the end of July he was convinced by "false astrologists" (according to the Byzantine chronicler Theophanes the Confessor) that the stars boded victory.  He attacked the Bulgarians in their prepared positions.

Victorious Bulgar warrior with captive,
featured on an ewer from the
 Treasure of Nagyszentmiklos.

Before the beginning of the battle, while awaiting the Byzantine assault, the Bulgarian ruler secretly placed part of his cavalry behind the hills surrounding the battlefield.
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The Byzantines, naturally, attacked in battle formation, but the uneven terrain led to a certain degree to its disruption, which was immediately used by Khan Kardam and the Bulgarian forces counter-attacked the enemy.  The Bulgarian counterattack was a great success against the disorganized Romans.


The hidden Bulgarian cavalry went round the Byzantines and cut their way back to their fortified camp and the fortress of Marcellae.  The Bulgarians took the supplies, the treasury and the tent of the emperor. They chased Constantine VI to Constantinople killing a great number of soldiers. Many Byzantine commanders and officers perished in the battle.
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A weapon called arkani was used by the Bulgarians in this battle: the arkani consisted of a long pole with an attachment similar to a lasso at one end. It was an excellent weapon against cavalry as the rider could easily be pulled out of the saddle by a skilled warrior, armed with the arkani.

Khans of the Bulgarian Empire.

The Aftermath
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It was a total and humiliating defeat for the Romans.  Constantine VI was forced to conclude peace with Kardam and had to pay tribute. Four years later (in 796) the emperor stopped the paying leading to a new war in Thrace which ended without a decisive battle.  The hostilities between Bulgaria and Byzantium continued under Kardam's successor Krum.
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The victory had great political significance. The decades of crisis were finally overcome, the Byzantines were forced once again to pay tribute to the Khans. Bulgaria entered the 9th century consolidated, stronger and united which was an important factor for the string of victories scored by Krum against the Byzantines.
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(Wikipedia)

VIDEO  -  681 AD: The Glory of Khan (Bulgarian: 681 г.: Величието на хана) is an 1981 three-part Bulgarian historical action and drama film telling the story of khan Asparuh and the events around the founding of the medieval Bulgarian state in 681 AD. It was shot and released on the occasion of the 13-century anniversary of Bulgaria.

The fortress of Markeli's Well Tower on the banks of the Mochuritsa.
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Markeli acquired its strategic importance in the late 7th century, when the establishment of the First Bulgarian Empire and its expansion turned it into a vital frontier stronghold just south of the Balkan Mountains. It would often change hands between Bulgarians and Byzantines, who would use it as a favourable starting point for military campaigns southwards and northwards respectively.

Markeli first came under Bulgarian rule in 705, when it, together with the whole region of Zagore, was ceded to Bulgaria by Justinian II.

Ruins of the basilica within the castle.
.Archaeological research of the fortress has been conducted since 1986. It has revealed that the castle was built in Late Antiquity (the early Byzantine period).  


The fortifications were constructed out of crushed stones with integrated rows of bricks and are thought to date to the reign of either Anastasius I (491–518) or Justinian I (527–565), i.e. the late 5th to mid-6th century. The ramparts were up to 10 metres (33 ft) high and had over 3-metre (9.8 ft) ditches before them.   he entire fortress, including the embankments dating to the early 9th century, had an area of 173 acres (0.70 km²).

The ruins of a Christian church (basilica) that have been unearthed in the eastern part of the castle are equally old as the fortifications. A well tower was positioned in the vicinity of the river in order to control access to the fortress and provide water for the defenders. An ancient bridge crossed the river near the tower, and an underground passage served as another way for the inhabitants to enter or leave Markeli.  

Overview of the castle ruins.
.In 792, Markeli was once more in the centre of a major Byzantine–Bulgarian conflict.  The second battle of Marcellae came during a long period of aggression between Byzantium and Bulgaria, with Bulgarian ruler Kardam and Byzantine Emperor Constantine VI each invading foreign territory in the past few years. Due to strategic errors, the Byzantines suffered a heavy blow in this battle.   

The Bulgarians and Romans at 800 AD.
The invasion of the Bulgarian people into the Eastern Roman Empire was one of
the greatest military challenges faced by any nation.  The Byzantine-Bulgarian Wars
lasted for nearly 800 years.

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.


Background

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.

FIGHTING WARS ON THREE CONTINENTS
Roman Emperor Constantine IV and his court.  He organized the military and city 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 620sMuhammad 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.

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 hisDecline 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.

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.

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.

The Theodosian Walls of Constantinople, which proved impregnable during the siege. (Byzantium 1200)

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. 

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.

Peace 

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 orarmatoli 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.
(gilbert1986.blogspot.com)

The horror of burning to death by Greek Fire would have given the Byzantines a huge edge in battle.
(gilbert1986.blogspot.com)

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.