First Bulgarian Empire

Founder of the First Bulgarian Empire; led his Bulgar tribal confederation across the Danube in 679–681 AD and defeated the Byzantine Emperor Constantine IV, forcing Byzantium to formally recognize the Bulgarian state and pay annual tribute — a remarkable achievement against the most powerful surviving Roman state; established the capital at Pliska in the Danube delta region

Son of Asparuh and one of the most consequential Bulgarian Khans; assisted the deposed Byzantine Emperor Justinian II in regaining his throne in 705 AD, receiving the title 'Caesar' from Byzantium — the only foreign ruler ever granted this Roman imperial title; crucially, his forces helped repel the first great Arab siege of Constantinople in 718 AD, earning Byzantine gratitude and cementing Bulgaria's role as a Balkan power

Maintained the Bulgarian state during a period of Byzantine resurgence under Leo III; his reign preserved the territorial gains of Asparuh and Tervel against Byzantine pressure to reassert Balkan dominance

Last Khan of the Dulo founding dynasty; his death without a clear successor triggered a prolonged succession crisis that saw six khans in less than two decades and temporarily weakened the Bulgarian state

First Khan of the Ukil clan; came to power amid the post-Dulo succession struggles; conducted border negotiations with the Byzantine Empire over the frontier in Thrace

His peaceful policy toward Byzantium was opposed by the Bulgarian military aristocracy; assassinated after concluding a peace treaty that the warrior nobility considered too favorable to Byzantium

From the Ugain clan; adopted an aggressive policy against Byzantium; defeated by Emperor Constantine V at the Battle of Anchialos in 763 — one of the largest battles fought in the Balkans in the 8th century; was killed by his own nobles after the defeat

Briefly held power after Teletz; attempted to negotiate peace with Byzantium but was overthrown within months by the war faction; fled to Constantinople, becoming the first Bulgarian Khan to seek Byzantine political asylum

Briefly held the throne during the continued succession crisis; conducted an inconclusive war against Byzantium; removed by the Bulgarian boyars

According to the Nominalia, ruled for only 40 days — the shortest reign in Bulgarian Khan history; the extreme brevity reflects the complete breakdown of stable succession during this period

Another short-reigning Khan of the crisis period; his brief rule preceded a slight stabilization under Telerig

Stabilized the Bulgarian state after a decade of chaos; conducted a successful deception operation against Byzantine Emperor Constantine V, tricking him into revealing his Bulgarian informants; fled to Constantinople in 777 but his reign marked the end of the worst succession instability

Longest-reigning Khan of the succession-crisis era; defeated Emperor Constantine VI at the Battle of Marcellae in 792 AD, forcing Byzantium to resume tribute payments to Bulgaria; his reign restored Bulgarian military prestige and stabilized the frontier for the final pre-Christianization generation

The greatest Khan of the First Bulgarian Empire; destroyed a Byzantine army and killed Emperor Nicephorus I at the Battle of the Varbitsa Pass in 811 — the first Byzantine emperor killed in battle since Valens at Adrianople in 378; made a drinking cup from Nicephorus's skull lined with silver, in the steppe tradition; sacked Serdica (Sofia) in 809 and Adrianople in 813; besieged Constantinople in 813–814 but died before the assault; his conquests doubled Bulgaria's territory and established the empire as the dominant Balkan power