Hercule became the World Martial Arts Chapion before the Cell saga. When the Cell Games began he entered but soon lost. The day after however all the papers said that he Was the one who destroied cell. Just before Majin Buu was about to be awakened a group of children did a skit to show how the thought the Cell Games turned out. When all the Z-fighters except #18 leaves he makes a deal with her saying if she threw the match that he would pay her twice the prize money. After Buu was threatening the people Hercule went to his house and ended up becoming friends. This is when Buu spit out the evil Buu which soon absorbed the good Buu creating Super Buu.

In GT Hercule is still the champ. His daughter Videl is married to Gohan. He also has a grand-daughter named Pan. He is still considered the strongest man in the world, but thats for the humans that don't know the Z fighters.

Powers
Hercules doesn't have any real powers, he has a set of gadgets he uses such as bombs disguised as game consoles. He is rumored to use a jet pack for flight capabilities but he is hardly seen using it. Though Hercules is not as strong as any of the Z Fighters he is strong for a normal man but his daughter Videl is much stronger than he is since she trains more than he does but Hercules is strong as he demonstrated his strenght by karate chopping 5 layers of wood, he is an acceptional hand to hand combatant but his skill is below almost every fighter in the Dragonball Z universe.