Sigurd the Mighty was a Viking earl who led Norse forces in conquests in Scotland. He was, by the limited history available from that time, a pretty good battlefield leader. But he wasn't always the most honorable of combatants. And after he betrayed a Scottish leader, he made the mistake of putting the dead guy's skull too close to his leg wound.
Think of the most metal way that a Viking could go out. Leading a burning ship on a raid into an enemy hold? Sounds cool. Simultaneous ax swings to the skull with his nemesis? That's good for an album cover. But what about cheating another warrior leader in a battle, decapitating that dude, and then dying because his infected tooth rubbed against an open sore in your leg? Slightly less metal, right?
But that's what happened to Sigurd the Mighty, a man born as a commoner who went on to be a great military leader under Olaf the White, a Viking sea king.
It all started when Sigurd's older brother, Earl Rognvald of Moeri, lost a son while serving King Harald in the invasion of islands of Shetland, Orkney, and Hebrides. Harald expanded Rognvald's holdings by granting him the Orkney and Shetland islands, but Rognvald wasn't interested in ruling those islands. So he returned to Norway and passed the title and lands of the Earl of Orkney to his brother, Sigurd, in 875.
Sigurd was pretty lucky to get an earldom all to himself, and he appears to have taken the responsibility seriously. He led troops during multiple campaigns and became known as Earl Sigurd the Powerful.
(Peter Nicolai Arbo, Public domain)
But he had trouble controlling the lands he had captured for the king. He built a stronghold in the Moray area of Scotland to project power, but the Norse were not popular that deep into Scottish land. So a local leader, Maelbrigd, became a thorn in Sigurd's side.
Sigurd sought to end his struggles with Maelbrigd once and for all. The men agreed to meet in honorable combat with 40 men each. But Sigurd didn't trust Maelbrigd to fight honorably, so he did that classic thing where he cheated first. He brought 40 horses, but he put two men on each horse. Maelbrigd, on the other hand, did fight honorably.
The 80 men of Sigurd's force won. Big surprise. And Sigurd told them to strap the heads of their enemies to the horses to celebrate. Sigurd, of course, strapped Maelbrigd's head to his own horse.
But Sigurd had a sore on his leg. And Maelbrigd's teeth rubbed against that sore and infected it. In one of the most unlikely kills in history, Maelbrigd killed his foe from beyond the grave with a mouth full of bacteria.
Sucks to be Sigurd.
By the way, you can learn more about the struggle between the Norse and Scottish for Orkney and the surrounding lands in The Orkeyinga Saga available here.