How did Edgar the peacful get its nickname?

There is no widely known historical figure or character named "Edgar the Peaceful." It's possible that you're thinking of a different name or character.

To help me find the information you're looking for, could you please tell me:

* What is the context of this nickname? Is it from a book, movie, game, or something else?

* What is the full name of the person you're asking about?

With more information, I'll be able to find the answer for you!