It’s not a household name but perhaps it should be (along with Arausio, Manzikert and so on).
The Battle of Kleidion was the climax of a decades long struggle between not only the Eastern Roman Empire and the Bulgars, but a personal war between Emperor Basil II and Tsar Samuel of the Bulgarian Empire.
Unfortunately, Fawlty Towers’ success means that Basil tends to be seen as a silly name, but Basil II was perhaps the single most capable emperor the Eastern Empire ever produced, up there with Alexius and John Comnenus (and, of the Western, Aurelian and Trajan).
After a prolonged period of being emperor in name only*, he finally took the reins in his late teens. His first campaign, some years later, against the Bulgars ended in disaster and almost cost Basil his life at the hands of Samuel. After this events drove him to focus his attention elsewhere before, as a more mature and capable man, returning to the Bulgars.
Although, at this period of history, the Byzantines had been enjoying success against the Saracens in the east, in the west, the Bulgars, under Samuel, had been building themselves into quite the powerhouse.
Basil II, the last of three great warlike emperors in a row, put a stop to this. Contrary to the stereotype (often but not always deserved) of a Byzantine emperor being a remote, palace-dwelling creature, he led from the front, and usually lived there too. The devotion of his army was ferocious, partly because he adopted the orphans of men who fell in battle and with whom he shared a father-son relationship, and he created the elite Varangian Guard (think Praetorian Guard, but composed of loyal Scandinavians rather than treacherous Romans).
Led by their great emperor, the Eastern Roman Empire started taking the Bulgars to task, and the pivotal moment of the war was reached at Kleidion. The Bulgars were defending a pass in significant numbers (hard to be precise, unfortunately), and initially repulsed the Byzantine assault. When Basil II sent men around to take the Bulgars from the rear, the battle was won, and Samuel himself almost captured. The Bulgar army dissolved into a rout, so it was not merely victory, but a crushing victory.
A huge number of men were killed in the rout, and 10,000 were captured. And its because of those 10,000 that Kleidion is best known. Basil, hereafter known as the Bulgar-Slayer, had them divided into groups of 100. Of those, one man was blinded in one eye, and the other 99 blinded in both eyes. The one-eyed man then acted as shepherd for his 99 companions, and the 10,000 were sent back to Samuel.
The Tsar, by this time old, ill, and suffering not only knocks on the battlefield but politically, reportedly saw the ruined remnants of his army and experienced a fatal heart attack.
The victory ultimately led to the Eastern Empire’s borders extending all the way to the Danube, for the first time in centuries. But it’s not the territorial advantage or the battle itself that made the battle live on, but the cruel fate meted out to the thousands of prisoners.
It also cemented Basil II’s reputation as a brutally successful man, whose uncompromising ruthlessness made the Eastern Empire stronger than it had been for hundreds of years.
*I may well write another piece on this, as it’s a rather interesting period.