The Secrets of Khan Asparuh: How he founded Bulgaria and what connects him to the Kazakh Dulat clan

In the 7th century, a people departed from the steppes near the Sea of Azov with nowhere to return. The Khazars had crushed Great Bulgaria, the five sons of Khan Kubrat scattered in different directions, and all that remained of the state their father had spent a lifetime building was a few thousand horsemen with their families and livestock. One of those sons, Asparuh, led his people westward - to the place where the Danube flows into the Black Sea and where marshy shores could shield them from any pursuit, El.kz reports.

Kubrat was born around 605 and grew up at the Byzantine imperial court in Constantinople, where he became a close friend of Emperor Heraclius. This was a rare occurrence in the history of steppe peoples: the future founder of a Turkic state was raised in the capital of the very empire that his descendants would later fight for generations.

Kubrat and Heraclius

In 632, Kubrat united the scattered Bulgar tribes into a single state with its capital at Phanagoria on the coast of the Sea of Azov. Great Bulgaria ranked second in power among European states after Byzantium. He drove out the Avars, to whom tribute had previously been paid, and concluded an alliance with Constantinople, receiving the prestigious title of patrician from the emperor.

Before his death, Kubrat gathered his five sons and instructed each of them to break a single spear. They did so easily. Then he tied the spears into a bundle and asked them to break them together. None could. The khan told his sons that if they remained united, no one would defeat them, but if they separated, they would be broken one by one. They did not listen. After his death around 665, the Khazars destroyed Great Bulgaria precisely because each brother defended only his own part.

Where did the Name “Bulgars” come from?

Scholars have debated this question for more than a century and a half, and no consensus has been reached. The most widely accepted theory derives the ethnonym from the Proto-Turkic word bulgha(“to mix, stir”) and its derivative bulgak (“rebellion” or “disorder”). Under this interpretation, the Bulgars were literally the “mixed” or “rebellious” people.

Flight as a Strategy

After Kubrat’s death in 665, the horde was divided among his five sons. Asparuh inherited the Onogundur tribe and found himself facing the Khazars, who took advantage of the Bulgars’ weakened state following the partition. By every standard of steppe politics, it was a catastrophe: Kubrat’s unified state, which had once intimidated the entire North Caucasus, fell apart within a few years.

Following the collapse of Great Bulgaria under Khazar pressure, Asparuh led the Onogundurs across the Dnieper and Dniester rivers and settled in Ongal, a triangle between the Danube, Siret, and Prut rivers. He chose the location carefully. The marshy Danube delta provided what the open steppe could not: natural protection on three sides and the ability to monitor enemy movements. The steppe warrior selected a position that no cavalry charge could successfully storm.

Asparuh leads the Bulgars

Asparuh understood that his people, weakened by division, needed additional manpower. He found support among the Slavic tribes living beyond the Danube in Thrace and Wallachia. The alliance was pragmatic: the Bulgars supplied military strength, while the Slavs provided people to guard borders and cultivate the land.

While Constantinople looked East

The Bulgars began crossing the river and settling new lands without resistance from Byzantium because the empire was engaged in war with the Arabs. It was a rare gift of circumstance, and Asparuh took full advantage of it.

After subjugating the local Slavic tribes, Asparuh adopted an aggressive strategy, launching attacks on Byzantine border fortresses and settlements near his newly established state. These raids were not mere plundering expeditions; they were calculated efforts to pressure the frontier and force Constantinople to respond. Asparuh sought to draw his opponent out of fortified positions and fight on unfavorable terms.

The first Byzantine response was successful: in 679, the army of Constantine IV defeated the Bulgars near Adrianople and removed the immediate threat to Thrace. Yet it was only a peripheral victory. Asparuh and his core forces remained in Ongal, hidden among the marshes of the Danube delta, beyond the reach of the emperor’s cavalry.

Ongal: The Battle won by a marsh

In 680, Byzantine Emperor Constantine IV launched a massive land and naval campaign against the Bulgars. He assembled troops from all the empire’s themes - the best forces Byzantium could muster. Part of the army advanced overland through the Balkan mountain passes, while another contingent sailed to the Danube estuary. The plan was to trap the Bulgars from two directions.

Asparuh chose a defensive strategy. The Proto-Bulgars repeatedly repelled attacks while preparing for a prolonged defense. After these failed assaults, the Byzantines laid siege to the position. For several days they hesitated to launch another offensive, likely because Bulgar cavalry had already inflicted losses and weakened their momentum.

Asparuh against Byzantium

The marsh proved more effective than any wall. Heavy Byzantine infantry became bogged down in mud. Cavalry could not gain speed. Supplying a stretched army at the edge of the empire grew more difficult with every passing day.

When Constantine, suffering from gout, left the army and traveled to Mesembria for treatment, Asparuh launched a counterattack and defeated the Byzantines. The emperor’s departure was interpreted by the troops as a signal to flee. An army assembled from across the empire collapsed into disorder.

The Treaty that changed Europe

Ultimately, the difficulties of maintaining troops on the imperial frontier forced Byzantium to sign a peace treaty in Constantinople recognizing the creation of a new Bulgarian state. This occurred in 681.

In the years following his victory, Asparuh undertook several important initiatives: he regulated relations with the Slavic tribes within the state, assigning them responsibility for guarding the southern and western frontiers; he campaigned against the Khazars, pushing them westward and expanding Bulgaria to the Timok River and the Carpathians; he strengthened the new capital of Pliska and restored the fortress of Drastar; and he built the Great Rampart—a defensive earthwork stretching from the Danube to the Black Sea.

Asparuh died around 700 during a campaign against the Khazars— - the very people from whom he had fled thirty years earlier. He had already achieved his greatest accomplishment: turning exile into a state. A Turkic khan with only several thousand horsemen compelled the most powerful empire in Europe to recognize him as an equal and pay tribute. Byzantium never forgot it.

Was Asparuh from the Dulat Tribe?

Here the story intersects with Kazakh genealogy, and the connection is not accidental. In the Western Turkic Khaganate of the 6th and 7th centuries, one of the two principal tribal wings was the Dulu, as recorded in Chinese chronicles. The Dulat tribe of the Senior Zhuz traditionally traces its lineage to these same ancient Dulu. The name of the Dulo dynasty almost certainly derives from the same Turkic root.

The connection is likely not one of direct descent but rather of shared origins. Several branches of an ancient tribal confederation appear to have diverged in the 7th century: some followed Asparuh to the Balkans, while others remained in the Semirechye steppes and later became part of the Kazakh Senior Zhuz. A common ancestor likely existed; a common history certainly did.

A Language That Disappeared in Three Centuries

The Proto-Bulgars spoke a Turkic language of the Oghur branch, related to Khazar and Volga Bulgar. Today, only Chuvash survives from this branch, spoken by about one million people in the Volga region. It provides linguists with a key to reconstructing Proto-Bulgar speech.

The Turkic language of the Proto-Bulgars did not survive long in the Balkans. By the 10th–11th centuries, it had disappeared completely, replaced by Slavic dialects. The reason was simple: the Proto-Bulgars formed the military and ruling elite but were greatly outnumbered by the local Slavic population. The adoption of Christianity in 865 under Khan Boris I accelerated assimilation. Church texts were written in Old Church Slavonic, worship was conducted in the same language, and Turkic speech gradually vanished from public life.

Modern Bulgarian contains roughly 2,000 words of Turkic origin, though most entered the language during the Ottoman period rather than from the Proto-Bulgars. The word “Bulgarian” itself is perhaps the most enduring legacy of the Turkic founders.

What the Genes Say

Genetic studies conducted particularly actively during the 2010s and 2020s present a complex but fascinating picture. Modern Bulgarians predominantly possess a European genetic profile similar to that of Serbs, Macedonians, and Romanians. Their Central Asian component is noticeably smaller than that found among Hungarians, whose Magyar ancestors migrated from the same steppes around the same period.

However, burials dating to the 7th–8th centuries within the territory of the First Bulgarian Empire contain remains with a pronounced East Eurasian genetic component -

evidence of people who genuinely came from the steppe. Within three or four generations, this component largely disappears from the archaeological record. Genetics confirms what history suggests: assimilation was rapid and comprehensive.

The Dulo Dynasty: From Attila to Its Fall

The “Nominalia of the Bulgarian Khans,” a brief list of rulers and reign lengths, begins with Avitohol, who supposedly ruled for 300 years, and Irnik, who allegedly ruled for 108 years. These are clearly legendary figures, but most scholars identify Irnik with Ernak, the youngest son of Attila, mentioned in Byzantine sources. Through this connection, the Dulo dynasty sought to legitimize itself by tracing its lineage to the most feared conqueror of the age.

The historically reliable portion of the dynasty begins with Kubrat and continues through Asparuh. His son Tervel became one of Bulgaria’s most capable rulers. In 705, he helped the deposed Emperor Justinian II regain the Byzantine throne and received the title of Caesar - an unprecedented honor for a so-called “barbarian” ruler. In 718, Tervel defeated the Arab army besieging Constantinople, and Europe may owe him a debt for helping halt Arab expansion at that point.

The last ruler of the Dulo dynasty was Sevar, who reigned until 753. After his death, internal power struggles erupted. Rival clans, the Ukil and Vokil, carried out bloody purges, many members of Dulo were killed, and the old Turkic dynasty disappeared roughly 80 years after the state’s foundation.

Asparuh’s Tamga

The tamga of the Dulo dynasty was the symbol IYI, sometimes described as a “double horn” or a “trident.” It has been found on stones, ceramics, and metal artifacts from the 7th and 8th centuries throughout the territory of the early Bulgarian state. The symbol was derived from Turkic runic traditions.

Bulgarians Remembered Their Steppe Brothers

One of the most telling episodes in the history of the First Bulgarian Empire was the Bulgarian rulers’ appeals to the Kipchaks for assistance. In the 11th and 12th centuries, as Byzantine pressure intensified, Bulgarian tsars actively recruited Kipchak warriors from the steppes north of the Danube. During the Second Bulgarian Empire, established after the Asen brothers’ uprising in 1185, Kipchak contingents played a decisive role in defeating Byzantine forces. In the early 13th century, Tsar Kaloyan fought alongside the Kipchaks against both the Crusaders and Byzantium.

This was more than a military alliance of convenience. The Bulgarian ruling elite preserved the memory of its steppe origins long enough to regard the Kipchaks as kindred peoples rather than mere mercenaries. The steppe did not forget its own.