Jack lived a pleasant life with his father, a samurai emperor, and his mother, the samurai's wife. Until Aku broke free and spread evil across the land and Jack fled with his mother to train across the world. Once his training was completed. He went after Aku but before he could destroy Aku, he used a time travel spell to send Jack into the future where Aku has conquered the world.
Samurai Jack: Battle Through Time - Sequel to the series. More details inside.
The Zone • View topic - Samurai Jack
Jack quests to travel back in time and defeat Aku before he can take over the world. Long ago in a distant land, I, Aku, the shape-shifting Master of Darkness, unleashed an unspeakable evil! But a foolish samurai warrior wielding a magic sword stepped forth to oppose me. Before the final blow was struck, I tore open a portal in time and flung him into the future, where my evil is law! Now the fool seeks to return to the past, and undo the future that is Aku! On his return, he faces and almost defeats Aku, but before he could land a finishing blow, Aku creates a time portal that sends the prince turned samurai into the distant future, with anticipation that he would be able to deal with the samurai by that time. The first people he encounters call him "Jack" as a form of slang, which he adopts as his name.