A long time ago, Frieza used the Saiyans as mercenaries to destroy the other planets for him. On one planet Bardock and his teammates destroy the life on the planet, but a surviver curses Bardock to be able to see his horrible future. The surviver is killed and Bardock returns to his planet. When that happened, his son Kakarotto(a.k.a Goku) is born. In addition to that, Frieza is under Zarbon's influence that the Saiyans could become a threat. At that time, Vegeta is only a kid with an extremely high power level for his age convinces Frieza to let him and Nappa go trigger happy on other planets. Bardock then leaves to destroy another planet. Bardock learns of Frieza's plan to destroy his home planet when he sees his teammates dead. He then encounters Frieza's henchmen and kills them, except for Dodoria. Dodoria threw a single fireball and defeated him. Bardock survives, but is seriously injured. Despite that, he went back to Planet Vegeta and warns them. They took it all as a joke and mocked him. He decides it's all up to him to save his planet. He flies toward Frieza's ship all pissed off. Hundreds of Frieza's henchmen fly towards Bardock, but he ends up kicking their butts. Bardock created his final fireball in attempt to stop Frieza. Frieza just laughs at him and creates this super fireball that overwhelmes Bardock's and continues to fly at the Saiyan planet. Bardock, Planet Vegeta, and Frieza's henchmen that were sent there, were destroyed. He sees his future one last time before he dies. He sees his planet destroyed... He sees Kakarotto grow up... And die happy. Vegeta was told that a big meteor came and destroyed his planet, but didn't seem to give a crap. Kakarotto's older brothers, Raditz and Thares, were somewhere else so they survived. As for Kakarotto, he lands on Earth and is taken in by Grandpa Gohan who named him Goku. I got all this info from Blaze's Dragon Ball page, so visit it, alright?