Europe in the Middle Ages was a bloody place, where poisoning wells and massacring your enemy’s peasants was considered an acceptable mode of warfare. So it is no surprise that Medieval kings and queens often resorted to assassination to get their way. Many of these murders changed the history of the continent, from the duke smothered with a mattress to the king stabbed by an assassin hiding inside his toilet.
10. William Longsword
William Longsword was the son of Rollo, the daring Viking chief who had converted to Christianity and founded the Duchy of Normandy in northern France. William continued his father’s work, aggressively expanding the duchy to the north. With France in turmoil, there was no central authority to stop him. There was just one problem: his lousy neighbor, Flanders.
As the Normans were expanding north, Arnulf the Rich, Count of Flanders, had been rapidly expanding south. The two sides collided in 939 in a dispute over Montreuil, sparking a brief but extremely bloody war.
Realizing he could not defeat Longsword in battle, Arnulf decided to finish things another way and invited his rival to a meeting on an island in the Seine in 942. William foolishly walked into the Flemish trap. As soon as he set foot on the island, three of Arnulf’s men burst out of hiding and hacked him to death.
William was succeeded by his ten-year-old son, who was soon kidnapped by the French king and spent the rest of his life struggling to hold Normandy together. Arnulf kept his new territories, and the era of rapid Viking expansion in France came to an end.