Johannes Liechtenauer
Although it's noteworthy to note that we're not totally certain if Johannes Liechtenauer existed, he is often regarded as the founder of early European martial arts. We only have references from other people's memories of him because there are no public records of his life.
However, it is evident from those documents that Liechtenauer was not only real; he may well have been the creator of the entire German school of fencing. The first known text relating to the school, even though the original book has been lost to time, was written by him. It describes a form of fencing that first appeared in the German parts of the Holy Roman Empire somewhere in the 14th century.
Although Liechtenauer was skilled with the two-handed sword, he also taught students how to use other weapons, such as knives and staffs. He traveled much, and after meeting and competing against masters from all around the world, he perfected his technique.