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

Wednesday, June 7, 2017

Rome Collapses the Bulgarian Empire - Battle of Kleidion

Middle Byzantine Arms and Armor
Vito Maglie of the group I Cavalieri de li Terre Tarentine wearing the 11th C reconstruction of the klivanion of St. Nestorius by Hellenic Armors.

"Basil the Bulgar-Slayer"
Ends The Bulgarian Empire

For centuries the Balkans provinces of the Roman Empire were assaulted by endless waves of barbarian tribes from Central Asia. But by far the most successful of the invading tribes was the Bulgars.

The Bulgars were semi-nomadic warrior tribes originating from Central Asia whose exact ethnic origin is controversial. They spoke a form of Turkic language and during their migration westwards they absorbed other ethnic groups.

The first clear mention of the Bulgars in written sources dates from 480, when they served as the allies of the Emperor Zeno (r. 474–491) against the Ostrogoths.   In the first half of the 6th century the Bulgars occasionally raided the Roman Empire.

By 681, the Eastern Romans were compelled to sign a humiliating peace treaty, forcing them to acknowledge Bulgaria as an independent state, to cede the territories to the north of the Balkan Mountains and to pay an annual tribute.

The campaigns of each side seesawed back and forth with neither empire able to overcome the other.

It was standard Byzantine practice to attack the Bulgarians whenever there was no active campaigning against the Arabs.

Tsar Samuel I

The last great Bulgarian enemy of Rome was Samuel, Tsar of the Bulgarian Empire from 997 to 1014

After defeating the Magyars in the north, Samuel, serving as a general, turned his attention south and in 896 routed the Roman army in the battle of Boulgarophygon. 

Virtually the entire Roman army was destroyed. 

Samuel led the Bulgarian troops to Constantinople, burning villages en route. According to the Muslim historian al-Tabari, Leo VI was desperate after the consecutive refusals of peace, and was forced to gather an army of Arab prisoners of war and send them against the Bulgarians with the promise of freedom. The Bulgarians were stopped just outside Constantinople and Samuel agreed to negotiate.

Byzantium was obliged to pay Bulgaria an annual tribute in exchange for the return of allegedly 120,000 captured Byzantine soldiers and civilians. Under the treaty, the Byzantines also ceded an area between the Black Sea and Strandzha to the Bulgarian Empire.

Samuel had proven himself a good general and a deadly enemy of Rome.  The wars go on and on even as Samuel becomes Tsar in 997. Many Byzantine fortresses fell under Bulgarian rule. The Bulgarian successes in the west raised fears in Constantinople causing Emperor Basil II to attack the Bulgars over and over.

The year 1000 saw a turn in the course of Byzantine-Bulgarian warfare. Basil II had amassed an army larger and stronger than that of the Bulgarians. Determined to definitively conquer Bulgaria, he moved much of the battle-seasoned military forces from the eastern campaigns against the Arabs to the Balkans and Samuel was forced to defend rather than attack.

The multi-year grinding showdown was beginning.

Basil II, The Warrior Emperor

It is a neck and neck race between the Emperors Heraclius (610 - 641) and Basil II (960 - 1025) for the best warrior Emperor.

In that contest Heraclius, to me, is the clear winner.  Heraclius totally crushed the Persians and saved a Roman Empire that was a blink away from total extinction.

Still Basil was unique. As both a general and Emperor he had no interest in living the easy life of the well born elites.  He fought and ruled from the saddle.

Basil was called "The Father of the Army".  He was worshipped by his troops. Instead of issuing orders from distant palaces Constantinople we see Basil living the life of a soldier with his troops and even eating the same daily rations as a common infantryman. All reports say he was a brave soldier and a fine horseman.

He also took the children of deceased officers of his army under his protection and offered them shelter, food, and education. Many of them later became his soldiers and officers and came to think of him as a father.

Basil successfully campaigned against the Arab Fatimid armies and marched as far south as modern Lebanon forcing a 10 year truce with the Caliph in 1001 which was renewed in 1011 and again in 1023.

Turning to the north, Basil acquired considerable territory in what is now southern Georgia. eastern Turkey and western Iran.  Basil also "persuaded" the ruler of Armenia to give the nation to Rome on his death.

The Empire achieved its greatest expansion ever directly to the east, in excess of all Roman conquests.

With the east secure Basil turned to Bulgaria.

Bulgarian Warrior Reenactors
(Screenshot HunHorda)

The Bulgarian Army

Originally the core of the Bulgarian Army was a force of heavy cavalry ranging from 12,000 to 30,000 horsemen. The reconquest of northeastern Bulgaria by the Romans reduced the recruiting grounds for the Bulgarians reducing the size of the cavalry units and making them more of a light cavalry force.

The Bulgarian army was well armed according to the Avar model: the soldiers had a sabre 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 called arkani. 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 armor and helmets. The horses were also armored. Armor was of two types — chain-mail and plate armor. The commanders had belts with golden or silver buckles which corresponded to their rank and title.

With the reduction of the cavalry the infantry's importance grew and the tactics changed to reflect the new conditions: the ambush, although employed in the past, now became the cornerstone of Bulgarian tactics.  During this period, the Bulgarians acquired a reputation for their skillful archers.

In the battle of Kleidion the Bulgarian army numbered around 20,000 soldiers. According some estimates the total number of the army including the squads of local militia reached a maximum level of 45,000.

The Roman Army

At this point the army numbered about 110,000 men.

The key is no one agrees as to the mix of troops.  Were 30,000 the regular standing units backing by local thematic troops?  40,000?

The core of the army were the tagmata regiments - the professional standing army of the Empire. They were formed by Emperor Constantine V after the suppression of a major revolt in the Opsician Theme in 741–743. Anxious to safeguard his throne from the frequent revolts of the thematic armies, Constantine reformed the old guard units of Constantinople into the new tagmata regiments, which were meant to provide the emperor with a core of professional and loyal troops. 

They were typically headquartered in or around Constantinople, although in later ages they sent detachments to the provinces. 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.

The Byzantine Empire's military tradition originated in the late Roman period, and its armies always included professional infantry soldiers. Though they varied in relative importance during the Byzantine army's history, under Basil II in particular heavy infantry were an important component of the Byzantine army. These troops generally had mail armor, large shields, and were armed with swords and spears. Under militarily competent emperors such as Basil II, they were among the best heavy infantry in the world.

Click to enlarge

Battle of Kleidion - July, 1014

Basil’s systematic campaign to reduce Samuel’s territory— and prestige—continued year after year.

The account in Scylitzes says:

  • "The emperor continued to invade Bulgaria every year without interruption, laying waste everything .... Samuel could do nothing in open country nor could he oppose the emperor in formal battle. He was shattered on all fronts and his own forces were declining so he decided to close the way into Bulgaria with ditches and fences."

Simply, Samuel would be overthrown by his own people if he could not defend the frontier against repeated Roman invasions.

To protect himself, as much as Bulgaria, Samuel gathered as large an army as possible for a showdown with the Romans. Some claimed his army was 45,000 strong.

Weakened as he was from endless Roman invasions that number was no doubt inflated.  The Tsar's forces were already in decline and manpower harder to come by.

Was the Bulgarian army 20,000?  25,000?  30,000?  There is no way to know. We can speculate that Samuel gathered everyone possible for this last fight. The fate of the nation was on the line.

Through spies Basil either knew of the gathering Bulgarian army and/or wanted to make a larger than normal attack.

Basil also gathered a larger than normal army. He prepared carefully and gathered to him some of his most experienced commanders. It appears that the truce with the Arabs allowed Basil to withdraw a number of regiments from the eastern front to use in the Balkan campaign.  A Byzantine army of 25,000 would be a bit larger than than the normal sized field army and might be close to the army that marched from Constantinople.

Struma River Valley
Emperor Basil's army marched up the valley to engage the Bulgarians.  The narrow nature of the valley allowed the Bulgarians to build defenses and hold off the Roman advance.

When Basil II set out to attack Macedonia once again, the stage was set for a major battle, which turned out to be decisive. It was fought in July 1014 in the Kleidion Pass.

Tsar Samuel's army of perhaps 20,000 or more deployed in a narrow gorge of the Struma River, between two mountains named Belasitsa and Ozgrazhden. In that gorge a strong wooden palisade was constructed on the lower slopes of each mountain to hamper the Byzantine advance. In addition, two strong towers were built to guard the flanks of the palisade.

Emperor Basil II's army (probably at least equal to the Bulgarian force) crossed the border. The Roman army followed a road that ran beside the Struma River, which had been a major route into the Bulgarian heartland in years past.

Here we find a situation much like King Leonidas at Thermopylae.  The valley is fairly narrow. Roman numbers and/or professional organization would not count for much. This allowed the defending Bulgarians an advantage. 

The Roman army was stopped by a thick wooden wall, defended by Bulgarian soldiers. The Byzantines attacked the palisade immediately, but were repulsed with heavy casualties.

With this small Bulgarian success, Samuel split his command. He tried to distract Basil by sending a portion of his army (several thousand?) under General Nestoritsa south to attack the Roman city of Thessalonika.

Roman troops under Theophylact Botaneiates, the strategos (Governor-General) of the city and his son Mihail managed to defeat them outside the city walls in a bloody battle. Theophylactus captured many soldiers and a large quantity of military equipment. 

With victory complete Theophylact marched north to add his victorious troops to Basil's army.

Bulgar warriors in a reenactment,
26 July 2006. Photo credit: Klearchos Kapoutsis

On about July 26 or 27, Emperor Basil's main army arrived in the narrow gorge of Kleidion Pass. Seeing the Bulgarian-built walls manned by thousands of soldiers, Basil ordered an immediate attack on them. The enemy, however, had erected their palisades carefully. 

The initial Byzantine attack was thrown back, suffering heavy losses. Over the next two or three days, several more attempts were made to breach the Bulgarian walls, to no avail. During that time, Botaneiates and his Thessalonikan soldiers joined Basil's army. Hoping their added weight would tip the balance in his favor, Basil threw them against the Slavic walls, to no avail.

Shades of Thermopylae

In the late afternoon of July 28, Basil was approached by his general Nikephoros Xiphias. The general offered to take several thousand Roman soldiers out of the main camp. They were to take mules with them, making it appear they were traveling south to replenish their supplies. They would then march over a steep mountain path to fall in the rear of the Bulgarian entrenchments. 

Basil gave his enthusiastic approval of the plan. Later that day, Nikephorus and his men left the Byzantine encampment, making a great show of their leaving. After traveling an hour or so south, the Roman force veered westward. Local guides directed them through steep passes of Mt. Belasitsa. By early morning of July 29, the Byzantine flanking force found itself in the rear of the Bulgarian lines.  Nikephorus ordered an immediate attack on the Bulgarian rear.

A surprise flanking maneuver and attack in a defender's rear is perhaps the most deadly of all military tactics.  The defenders always have peace of mind knowing their back is secure. Once an enemy shatters that feeling of security the defending army almost always panics and runs for safety.

That story repeated itself here. The Bulgarians were taken completely by surprise, now finding themselves hard-pressed from front and rear. The Bulgars and their Slavic kinsmen abandoned the towers to face the new threat. With defenses abandoned Basil's army was able to break through the Bulgarian wall and come to grips with the defenders.

In the confusion of the rout, thousands of Bulgarian troops were killed and the remainder desperately attempted to flee westwards.

Tsar Samuel had been absent from the battlefield that day miles to the west in his fortress at Strumitsa, conferring with his son, the Tsarevitch Gabriel Radomir. Upon receiving word of the battle, both men gathered their personal retinues and rode eastward to join the fight.

Samuel attempted to rally his troops near the town of Makrievo. Unfortunately, the battle was basically over and the Bulgarian army was in full rout. At one point, the tsar either dismounted or was unhorsed trying to urge his men to fight. Realizing the danger, Radomir grabbed hold of his father and put the old man on the tsarevitch's horse, and the two men rode together to escape the Byzantine pursuers.

The battle of Kleidion was over.

Cavalry vs Infantry

Again we lack so much detail on this battle.  Byzantine cavalry was the mailed fist of the army.  But in this case I doubt that cavalry played much of a part until the latter part of the battle.

It would have been the infantry (not horses) assaulting the dug-in Bulgarian wooden palisade.  I suspect it would have also been infantry sent up steep mountain paths to flank the Bulgarians.  Once the flanking attack was taking place it would likely have been infantry (or dismounted cavalry) punching through the Bulgarian palisade to make holes for the cavalry to ride through.

This would have been another victory for the perpetually ignored Byzantine infantry.

The Byzantines defeat the Bulgarians (top). Emperor Samuel dying at the sight of his blinded soldiers (bottom).

A Setback and Mass Blindings

After his victory on 29 July 1014, Basil II marched westwards and seized the small fortress of Matsukion near Strumitsa, but the town itself remained in Bulgarian hands. 
With things looking fairly secure the Emperor sent an army led by one of his most capable generals, Theophylactus Botaniates, to destroy the palisades to the south of the town. Thus he would clear the way of the Byzantines to Thessalonika through the valley of the Vardar river.

The historian Vasil Zlatarski specifies the battlefield at the Kosturino gorge between the mountains Belasitsa and Plavush. The Byzantines could not organize their defense in the narrow pass and were annihilated. Most of their troops perished including their commander. 
Botaniates was killed by the heir to the Bulgarian throne Gavril Radomir, who pierced the Byzantine general with his spear. Upon the news of that unexpected and heavy defeat, Basil II was forced to immediately retreat eastwards and not through the planned route via Thessalonika.

In retaliation for the death of Botaneiates, Basil ordered the blinding of between 8,000 to 15,000 Bulgarian prisoners.

Basil was in a foul mood, considering he had lost of one of his favored generals Botaneiates in an ambush. He pronounced that the Bulgarians, once vassals of the East Roman Empire, were traitors and would be punished thusly. 

The Bulgarians were divided into groups of 100 men. All the men in each group were blinded, save for one man who was left with one eye. Then, these thousands of men were released to roam the mountains, hoping to find their way back to the Bulgar capital. In early October, some of these groups found their way to Samuel's capital. 

As the mutilated men were paraded before him, the shock and horror of the treatment of his soldiers was too much for the tsar. He fell into an apoplectic fit, and went into a coma. Two days later, he died. As a result of his treatment of the Bulgarian prisoners, Basil acquired the nickname of "Basil Bulgaroktonos" or "Basil the Bulgar-Slayer."

Middle Byzantine Armor
11th C Dekarkh of Skutatoi - Rick Orli's group Stratēlatai Tagma.
Just one of a number of infantry impressions from this period.


The Bulgarian state and army were fatally weakened by Kleidon. 

Byzantine casualties are unknown. By contrast, the Bulgarian army was almost completely destroyed. The Byzantine victory essentially destroyed the Bulgarian Empire, though it would take another 4 years of mopping up before Bulgarian lands were consolidated into the Roman orbit. 

As a result of the battle of Kleidion, the Bulgarian army suffered heavy casualties that could not be restored. The ability of the central Bulgar government to control the peripheral and interior provinces of the Empire was reduced and power gravitated into the hands of the local and provincial governors. Many of them voluntarily surrendered to Basil rather than continue a war they knew would end badly for them.

The battle also affected the Serbs and the Croats, who were forced to acknowledge the supremacy of the Emperor after 1018. The borders of the Roman Empire were restored to the Danube for the first time since the 7th century, allowing control the entire Balkan peninsula from the Danube to the Peloponnese and from the Adriatic Sea to the Black Sea.

Click to enlarge
First Bulgarian Empire, early 10th century.

Click to enlarge
Bulgaria under the rule of Tsar Samuel
Campaign after campaign saw Roman armies probe deeper
and deeper into the Bulgarian Empire.

Click for full sized map

Click to enlarge
The Roman Empire of Basil II
Basil not only stabilized Roman borders in the east, but also conquered new lands and added them to the Empire.
But Basil's return of the Balkans to Roman rule was a monstrously huge achievement.

(Byzantine army)    (Bulgarian army)    (Bulgarian Empire Military)

(Bulgarian Empire)    (Grand strategy)    (Kleidion)    (Kleidion)

(Basil)    (Samuel)    (Wars)


Anonymous said...

Pretty work gary .
On the subject. The randon victories , and defeats , on short year gaps , doesn`t allow to have a quiet life on all the regions of the empire . Borders are easely broken , as fortifications scarce , and useless , cause they pass it trought .
If Bulgars a nuisance , the arabs , and after the seljud a more dangerous foe .
The empire need time , and reforms to face eastern troubles , cause armenia men are the main resource for the army . As armenia fall , things will go downhill as it was after Manzikert .
Only the cruzades change the situation for a few years .On good and evil also .
Neverdeless those resistance , allow europeans nations to grown bigger and stronger , and undefeatable . If they are even closer , or allied , things will be diferent .
But thats history .
On those last centuries , all that came around is a desire for peace on all lands , and peoples , whatever a few zelots do .

Anonymous said...

Gary , is time for a new Post !!!!

Gary said...

Having a summer moment. Sitting on the beach makes historical research look boring.

Anonymous said...

hope you not in Chris Christie New Jersey closed beach !!!!
as you a californian maybe you not in it surely .
research about austrian habsburg clampdown on invaders after byzantium fall ... its a vivid and lively history ... of how a small bunch of austrian ( nórica )mountaneirs , and a few germans , slavic allies , and hungarians , and naval fierce spaniards , had their finest hour ...

Anonymous said...

now they look , ... with a few exceptions ... a bunch of pussies

Anonymous said...

already a month , without a new Post ?
c`mon !!!!
give us something about Byzantium empire beach holidays , or something like that ...
Where they go ?
Or they don`t go , cause it`s not a civilized thing to do , in those times ?

Gustavo Pedroza said...

Parabéns pela matéria.No ocidente pouco se conhece sobre os conflitos nos Bálcãs.