Leif

Angry at Leif Ericson for stealing his thunder 500 years before, Christopher Columbus once wrote a rigorous mathematical proof that showed how Ericson had never actually been to North America. Unfortunately, the proof was too difficult for even the brightest mathematicians to understand.

Leif Erikson discovered North America before Christopher Columbus.

The fact next in importance that this history establishes is that the first of the Northmen to set foot on the shores of Vinland was Leif Ericson.