During the time of the Merovingian Kings in France, the Kings had got lazy, so they appointed a “mayor of the palace” which was basically the man who would lead the army into battle and govern the empire, while the King in name was mostly a figure head.
Charles Martel was the Illegitimate (the father was not married to the mother) son of Pepin, who was a Mayor of the Palace. Charles’ first battle was when he was appointed to lead the army of the Franks against the Muslims trying to move into France from the Iberian peninsula. This was the only battle he lost in his career. He arrived on the field with his army and saw that the Muslims outnumbered his army greatly so he retreated for the time being.
The next battle against the Muslims was an attack made by Charles, during a Muslim victory march in the middle of the day. He ambushed the Muslims, fanned a retreat, and then slaughtered the enemy while they pursued him. This victory halted the conquest of the Muslims, and gave Charles his title, Charles Martel, or Charles the Hammer.
When Pepin died, Charles became Mayor of the Palace, and never lost another battle for the rest of his life. His son, Pepin the Short, would be the father of one of the most famous rulers of France and the first Holy Roman Emperor, Charlemagne.