One of the greatest Jedi Masters of the Old Republic, he was the Grand Master of the Jedi Order during the last years of the Old Republic. He trained Luke Skywalker in the ways of the Jedi and has even faced characters like Asajj Ventress, Count Dooku and Darth Sidious and lived to tell the tale. He was the Jedi Master of former Jedi Knight Dooku, and he was also a mentor to skilled Jedi Knights such as Qui-Gon Jinn, Obi-Wan Kenobi, Anakin Skywalker and Ahsoka Tano.