Battle of Kleidion: Byzantines Defeat Bulgarians, Basil "the Bulgar-Slayer" Triumphs

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Battle of Kleidion: Byzantines Defeat Bulgarians, Basil "the Bulgar-Slayer" Triumphs

"The Byzantines under Emperor Basil II defeat the Bulgarians"
Illustration in 14th century Manasses Chronicle; manuscript in Vatican Library, Rome
(Unless otherwise indicated, all illustrations are courtesy of Wikipedia)

Today in Military History: July 29, 1014

I fully intended to write about another military event for today. However, after I related the story of the aftermath of this battle to a co-worker, he said, "Oh, you *have* to blog about that!" So, by popular demand, I give you the battle of Kleidion, one of the culminating fights in the Byzantine-Bulgarian War, sometimes called the "Fifty Years' War."


Near the end of the 10th century, the East Roman Empire (aka Byzantine Empire) was still a powerful player in European and Middle Eastern politics. Though greatly reduced from its former glory of the mid-sixth century, the core of the empire in Asia Minor, the Aegean and the Balkans was still basically intact.

However, the Romans' most immediate concern was the First Bulgarian Empire. Comprised of former nomadic peoples from what is today Russia, the Bulgars crossed the Danube River and established themselves in portions of modern-day Romania and Bulgaria. They intermarried with the native Slavic population, forging a new national identity. The First Bulgarian Empire was established in the latter decades of the seventh century. They fought several conflicts with the Byzantines, usually coming out on top. At one point, the Bulgarians forced a treaty on the East Romans, which included an annual Byzantine subsidy to the Bulgarians. The relationship constantly evolved; in AD 717 the Byzantine capital of Constantinople was besieged by a large Arab army. The Roman emperor appealed to the Bulgarians for help, and 30,000 Bulgarian soldiers helped to relieve the siege.

Over the next three centuries, the Bulgarian lands expanded and contracted as they fought intermittent wars with the Byzantines, the Hungarians, the Pechenegs, the Avars, and Kievan Rus. In 968, the Rus under Svyatoslav I invaded Bulgarian lands, capturing the capital of Preslav. Three years later, a Byzantine army drove the Rus out of the city. Unfortunately, the Romans took with them the Bulgarian treasury, the tsar's regalia, and a large part of the royal library. A final humiliation came when a public ceremony was held in Constantinople, where the Bulgarian tsar was ritually divested of his royal insignia. This was meant to symbolize the dissolution of the Bulgarian Empire. In addition, the Roman emperor declared the eastern portion of the Bulgarian lands as a new Byzantine province.

Map of Southeastern Europe, c. 1000 AD (Byzantine lands in pink outline) From 'Freeman's Atlas to the Historical Geography of Europe' edited by J.B. Bury, 3rd ed. (1903)
Map of Southeastern Europe, c. 1000 AD (Byzantine lands in pink outline)
From "Freeman's Atlas to the Historical Geography of Europe" edited by J.B. Bury, 3rd ed. (1903)

However, the Byzantines were unable to take control of the western provinces of Bulgaria, mainly due to the resistance of the Cometupoli brothers. During the course of the next 25 years, each brother died until only the youngest, Samuel, was left. He had been a successful general for over 20 years, fighting the Hungarians, Kievan Rus and Byzantines. As the last surviving brother, in 997 Samuel was declared the new tsar of Bulgaria.

For the next 17 years, Tsar Samuel led the Bulgarians in a war of survival against the East Romans. He managed to expand Bulgarian territory, including areas of modern-day Greece, Albania, Serbia, Macedonia, Bulgaria and southern Romania. Despite these successes, the Byzantines under Emperor Basil II began to launch annual attacks on Bulgarian lands.

Bulgarian Military

By the early eleventh century, the Bulgarian army had evolved from the all-cavalry model of their remote ancestors. Heavy cavalry still made up at least 15 percent of the armed forces, dressed in chainmail or scale mail and shield, carrying spears, sabers, and composite bows; the horses also wore leather or chain barding. Light horse archers comprised a larger portion, with unarmored men wielding bows, sabers, and lassoes. With the loss of their eastern lands in Thrace and eastern Bulgaria – prime horse-raising area for the military – the majority of the Bulgarian army was composed of Slavic spearmen, swordsmen, and foot archers. The spearmen were usually dressed in scale mail with shields, the swordsmen and archers wore almost no armor.

Early Bulgar spearman, c. AD 1000 (Illustration courtesy of
Early Bulgar spearman, c. AD 1000
(Illustration courtesy of

In addition, the nearly 50 years of constant war with Byzantium had sapped both the manpower of the Bulgarian state and the citizens' very will to resist. As a result, the Bulgarian army began to evolve a more defensive posture. Tsar Simon ordered ditches dug along the Bulgarian-Byzantine border, with defensive walls and towers built at choke points to delay enemy invasions. Ambushes became the Bulgarian military's major stratagem.

Preliminaries to the Battle

In the spring of 1014, anticipating the coming Byzantine invasion, Tsar Samuel raised an army estimated at between 20,000 and possibly 45,000 men. In early July, this force gathered east of the town Strumitsa (modern-day Strumica in eastern Macedonia). It 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.

Byzantine Emperor Basil II began raising another large army to invade Bulgaria (the sources do not give a figure for the size of this army, but it was probably at least equal to the Bulgarian force). Crossing 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.

When Samuel received word of the latest Byzantine incursion, he split his army and sent out 15,000-20,000 men under one of his ablest noble-generals Nestoritsa. Their job was to strike south into Roman territory and threaten the enemy's second largest city and major port, Thessalonika. It was also hoped that some portion of the invading army would be drawn off. This hope was dashed when the governor-general of Thessalonika, Theophylact Botaneiates, led his garrison out to meet the Bulgarian threat just outside the city walls. He defeated the enemy while taking many prisoners and a great amount of military equipment. Afterwards, Botaneiates led his men north to join Basil's main force.

Battle of Kleidion

On about July 26 or 27, Emperor Basil's 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.

Battle of Kleidion, July 29, 1014 (map courtesy of Wikipedia)
Battle of Kleidion, July 29, 1014 (map courtesy of Wikipedia)

In the late afternoon of July 28, Basil was approached by his general Nikephorus Xiphias. The general offered to take several thousand Byzantine 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.

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. They fought hard, but were eventually overwhelmed by the Romans. Many Bulgarians were killed, and many others surrendered. 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. By this point, the battle of Kleidion was over.

'Battle of Kleidion,' illustration from Skylitzes Chronicle, late 11th century (Chronicle located in National Library of Spain, Madrid)
"Battle of Kleidion," illustration from Skylitzes Chronicle, late 11th century
(Chronicle located in National Library of Spain, Madrid)


Byzantine casualties – like their initial numbers – 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.

Footnote #1: In the aftermath of the battle, Botaneiates and his men were ordered to advance to the town of Strumitsa and demolish a palisade erected across the road to Thessalonika. A few days later, they accomplished this mission. However, on the way back east to the main Byzantine army, they traveled through a narrow gorge and were ambushed by Slavic militiamen. The entire Roman force was wiped out. As a result, Basil ordered his army to withdraw back to Byzantine territory.

Footnote #2: I saved the best for last…

According to one historical source, the Byzantine army was holding between 14,000 and 15,000 Bulgarian captives as a result of their victory – another source claims it to be more like 8000 men. 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."

Tsar Samuel lies dying after seeing the treatment of his soldiers by the Byzantines - Illustration in 14th century Manasses Chronicle; manuscript in Vatican Library, Rome
Tsar Samuel lies dying after seeing the treatment of his soldiers by the Byzantines
Illustration in 14th century Manasses Chronicle; manuscript in Vatican Library, Rome

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