I think it's a pretty widely-accepted fact these days that one of the most badass fucking things any hardcore medieval warlord could possibly do would be to cut off the heads of his vanquished foes and fashion drinking cups out of the skulls of his slain enemies. The 9th century Bulgar horse lord Khan Krum the Horrible is, in my experience studying badass history, one of the only people to ever actually pull off this towering feat of brutal head-cleaving amateur carpentry – a gruesomely-awesome corpse-mutilation made all the more noteworthy by the fact that he dished this painful-yet-delicious justice out not just to any random douchebag with a homemade crown and a bearded, stick-swinging warband, but to the almighty Emperor of Byzantium, and that he carried it out just days after that Emperor pillaged Krum's capital city and stole all his booze.
The son of (we believe) a Bulgar father and a Slavic mother, Krum rose to power in Eastern Europe at a time when diplomatic power was a direct result of being a badass motherfucker. A ferocious war-loving berserker, unbeatable in single combat, and about as humorless as that one movie where Adam Sandler plays his own twin sister, this guy was so over-the-top fucking merciless that he's alternately remembered through history as Krum the Horrible, Krum the Terrible, Krum the Dreadful, and Krum the Other-Words-That-Mean-Bad... basically if it's a synonym for "cold-hearted bastard", you can fashion it into an epithet for the Bulgar Khan and it would fit him like Cinderella's glass slipper fit perfectly when Krum took it and rammed it up the ass of the last King of the Avars.
I prefer to think of him as Khal Drogo, only with more Emperor-killing goodness.
Thanks to his own personal scariness and wanton destruction of all who stood before him, Krum was declared Khan of the Bulgars in the year 803. He immediately went to work crushing all in his path and assembling one of the greatest and most expanisve Eastern European empires of the Dark Ages. At the head of a rampaging group of horsemen well-versed in steppe warfare and the finer arts of plundering the fucking shit out of everything and everyone they encountered, Krum led his warriors – mostly Bulgars, Slavs, Thracians, and Hellenized Macedonians – across the Carpathian mountains, over the Danube River, and throughout Transylvania, Thrace, and Macedonia. Cutting men down in single combat, Krum rode at the head of his forces, collecting the skulls of slain kings for his own personal head collection.
After destroying a couple barbarian tribes in a volcano of blood and disembodied organs and carving himself an empire that stretched from Budapest to the Ukraine, Krum the Horrible ordered his men to ride south into Byzantine lands, destroyed a mercenary Byzantine army near the Strymon River, and besieged the traditional regional capital of Thrace (present-day Sofia) in 809. Of course, as a horse warrior in a similar vein as Attila the Hun, Krum didn't have much in the way of siege equipment – he could surround the city and starve it out, but he had no way to assault the walls and bring about swift death/mayhem/etc. So, Krum the Horrible offered the good people of Sofia a deal: If you guys surrender the city, we'll grant you safe passage and let you leave with your lives.
The Byzantines accepted. As soon as they were free of the walls he massacred all 6,000 defenders and burned the city to the ground.
That might seem a little harsh, but badass, no-bullshit insanity is what Khan Krum the Horrible was all about – this guy's name isn't that similar to that of of Conan the Barbarian's God merely by coincidence. Just look at the hard-as-hell legal code this guy instated in his lands – robbery was punished by breaking both of the thief's ankles. Denying alms to a beggar resulted in the Khan taking your shit so that you could know what it was like to have nothing. Defamation and Internet Trolling and bitching about the endings of your favorite video games was punishable by death. This guy wasn't fucking around, and for the most part people listened. The only thing they had trouble with was Krum's order to ban alcohol in the empire, and his mandate that all winemakers rip out every grapevine in their vineyard. That was one law they had an OK time ignoring, mostly because what the hell kind of barbarian warlord doesn't like booze?
But back to the whole Byzantium situation. Back in the early days, before all the burninating the countryside business, the Greeks and the Bulgars had a pretty tentative love/hate relationship thing going on. The Bulgars were basically like a badass tribe of mercs that the Byzantines could call in whenever they needed to have someone turned into sludge – rampaging Bulgar horsemen had helped violently depose a couple of Greek Emperors, and they'd been called in to fight off a Turkish invasion or two, and for the most part as long as the Greeks had the gold, the Bulgars had the steel. Ok, sure, that was great and everything, but the Byzantine Emperor Nikephoros didn't really like the idea of a highly-organized tribe of motivated, kill-happy Bulgars cohesively unified under the command of a powerful badass who loved nothing more than to bathe in the blood of his destroyed enemies, so Emperor Nick decided that he needed to get off his ass and do something about it. He put together a large force of Byzantine troops and foreign mercenaries, marched into Khan Krum's lands, defeated the Bulgar leader on his home turf (Krum was not expecting a full-scale invasion by Byzantine forces and was driven off once he realized he had nowhere near enough manpower to deal with the Emperor's army), and then marched a triumphant, rowdy, stab-happy army of plunder-seeking mercenaries into Khan the Horrible's capital city.
The mercs weren't kind. The city was burned, civilians were dragged into the street and murdered, and Krum the Horrible's personal palace and treasury were stripped down to the studs and hauled off (as a side note, when the Byzantines entered Krum's cellar, they found it stocked to the ceiling with bottles of the world's rarest and most expensive wines... I guess he wasn't as hardcore about temperance as he might have wanted everyone to believe).
But Krum wasn't about to let the Byzantines get away with this bullshittery. He had wisely withdrawn in the face of an overwhelming Byzantine force, but instead of just running into hiding, the Bulgar Khan withdrew into the interior of his land and put out a call for every able-bodied man, woman, and animal to join his cause and teach those Byzantine bastards what happens to jackasses who try to mess with a dude known by the epithet "the Horrible". He built a huge army, mostly of peasants, quickly circled around the slow-moving column, and set a trap for them in the mountain pass that linked Bulgar lands to Byzantium.
Emperor Nicephoros was marching his long column through the pass, content in his victory and the deliciousness of the Bulgar Khan's favorite wines, when suddenly he heard shouting from the mountains above him. His scouts rushed ahead, only to find that both the entrance and the exit of the steep pass had been barricaded – the column was trapped. Then, with a ferocious battle-scream, the Bulgars rode down from the hills, hammering the strung-out column from all sides in a ferocious frenzy of steel and teeth that quickly became a blood-drenched massaacre.
The Emperor Nicephoros was killed in battle, making him one of just a few Byzantine rulers to ever perish in combat. The dead Emperor, identified by his purple boots, was dragged to the Khan's tent, where Krum the Horrible promptly cut off his head and put it on a pike. He kept it as a trophy for a while, then eventually scooped out the brains, lined the skull with silver, and turned it into a drinking cup (how do you like my wine now, bitch?). From that point on, any time Byzantine diplomats would come to negotiate with him, Krum would force them to drink wine out of the skull of their dead Emperor.
Krum toasting his victory with the severed head of his enemies.
The Emperor's son-in-law, Michael Rhangabe, survived the massacre by bravely running for it on horseback and swimming across a river, and was appointed Emperor on his return to Constantinople (the Emperor's birth son, Stavracius, also survived, but he'd been hit in the neck during the fight and was paralyzed from the waist down, so he wasn't really a great candidate for the throne). Emperor Michael, having now been face-to-sword with a Bulgar warrior, immediately tried to sue for peace. Krum said he'd agree, but only if Michael would hand over a bunch of douchebag Bulgar defectors that were currently living in Constantinople so that Krum could publicly execute them in brutal and horrible ways. Michael said he wasn't sure about that, so Krum said, "ok, fuck you buddy," and let his men on a massive raid into Byzantine lands. His forces swept across the Black Sea coast, plundering and pillaging wealthy cities and carrying off their populations as slaves. Krum the Horrible, who by this point was rocking some pretty primitive siege engines (he'd taken in an Arab ex-pat who had taught him about the magic of the flaming catapult attack), started hitting bigger and bigger cities, bringing back treasure and loot and babes and delicious foods to his capital.
Michael rushed out to fight the Khan, and was defeated in such a humiliating manner that Michael resigned his position as emperor on the spot and went off to be a monk. Michael's successor, Emperor Leo, also tried to stop the Bulgars, but got his asss kicked almost as hard. Krum went so far as to besiege Cosntantniople, but couldn't take it because he didn't have a fleet or a big enough catapult, so just raided the suburbs and then headed on home.
Khan Krum the Horrible died in 814 of a cerebral hemorrhage, which came about spontaneously while he was thinking about how awesome it was that he'd defeated three Byzantine Emperors in battle. Krum's successors ended up making peace with the Byzantines, and the First Bulgar Empire would last for another 200 years, finally dissolving in 1014.
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