TIL historians don't know why important warlord Ivar the Boneless was called "boneless." Theories range from him losing a leg to impotence & beyond.

https://en.wikipedia.org/wiki/Ivar_the_Boneless

https://www.reddit.com/r/todayilearned/comments/1522yr7/til_historians_dont_know_why_important_warlord/