Surfeit of lampreys
The youngest son of William the Conqueror scrambled onto the throne in 1100. His older brothers, one in charge of England, the other of Normandy, had made everyone's lives hell for years with their squabbles. Henry resolved to do better and came up with a Charter of Liberties. This worthy claim to fame, which won him the title Lion of Justice, promised fairer government and went on to form the basis of the Magna Carta.
To further tame his troubled kingdom, the Lion also married a Scottish princess. Matilda was a Saxon lass by descent so the wedding united the English and Norman lines for the first time. To those two achievements could be added his fluency in the native lingo, the first Norman king of England to be so, and his scholarly mind. Henry was a clever, well-educated man, interested in natural history and founder of the country's first zoo at his palace in Woodstock.
His constant troubles across the Channel resulted in another claim to fame.
In 1120, victory over Louis the Fat ended in loss when his beloved son William was drowned on the journey home - thanks to an excess of good wine and bad navigation. It was said that Henry never smiled again. But not even that very human tragedy secured his place in the history books.
No, what everyone knows about Henry, Lion of Justice, is his liking for a rather repulsive marine creature - a prehistoric, boneless eel-like predator with a ghastly sucker of a mouth and a taste for the blood of other fish.
Lampreys were a delicacy in the Middle Ages and their dark meaty flesh tickled the King's palate. So, on December 1, 1135, against the advice of his physician, he treated himself and tucked in. Alas, the fish were off, and the next day so was the King. Off to his grave, courtesy of that most famous cause of death, "a surfeit of lampreys".