Old Ben is a wise jedi, and one of the few members of the jedi order to survive the extermination process brought about by the evil Darth Vader. He plays a key role in the training of the jedi knights, and in fact two of the most influential jedi in Star Wars history are his own students. He himself was trained by Qui-Gon Jinn, a kind jedi, but also one who tended to rebel slightly against the ways of the jedi council. He was not dark in any way, but he was not a part of the council for a reason.

After the death of his master, and the subsequent duel against Darth Maul, Obi-Wan became a full jedi, and took it upon himself to train Anakin Skywalker in the ways of the force (a promise he made to Qui-Gon in the fallen Jedi's last moments). There is nothing he or any other jedi could do though, Anakin was destined to follow a dark path, and bring balance to the force, just as the prophecy foretold. Obi-Wan retreats and hides on Tatooine after the jedi are all but extinct.

The Force was not done with him yet though, and working in its regular mystical ways, it brough Luke Skywalker, the son of Vader to Obi-Wan. This was Obi-Wan's chance to bring back the jedi, and stop the evil Empire. Though he is struck down by Vader in Episode 4, he has already done enough to set Luke on the right path. With the help of Yoda, Luke becomes a powerful jedi master and restores the jedi order.

Obi-Wan also makes numerous reappearences in spirit form after his duel with Vader, and is able to give Luke advice, and keep him on the right path. For example, his advice at the Battle of Yavin allows Luke to destroy the Death Star, and later he also guides Luke towards Yoda for further training before the confrontations with Vader.

It is many years later when Obi-Wan finally moves on, leaving Luke to manage the jedi. Obi-Wan's work was complete, and the jedi restored, but over the years, many jedi had lost their lives at the hands of his apprentice, Darth Vader.