Martian Manhunter/Origin

Background History
J'onn J'onzz was a middle aged Martian who lived happily with his wife and two children on Mars. There was a strike on Mars from a foreign race which disturbed the peace, J'onn took part in fighting back against the invaders. He and his strike team were successful but all of them lost their lives and J'onn transported to earth with no memory of his wife or children, only that he was from Mars. After being stranded for decades on Earth, he came to love the planet as his alias John Jones. After being discovered by Superman as an alien, he is offered the chance to become more then just a martian, a superhero. J'onn J'onzz then took up the superhero persona, Martian Manhunter.

As Martian Manhunter, J'onn helped to start the Justice League alongside many of his close superhero colleagues. J'onn J'onzz now feels he owes a great debt to Earth for giving him another chance as something important, and is very loyal to both it and his home planet.