Born and raised in Sheboygan, Wisconsin, Greg Willis led a perfectly normal life until the summer before his senior year of high school, when he and his parents went boating on Lake Michigan and encountered a freak wind storm. Greg was overcome by the force of what appeared to be a miniature black-hole singularity in the sky above them and he was sucked into the singularity. When the storm passed, his parents found him in the lake. Weeks later, he discovered that he had gained superhuman powers.
When Greg came to Manhattan to attend New York University, he planned to join the ranks of New York's super-hero population, even intending to market his image. In his first costumed exploits as Gravity, he intervened during a battle between the New Warriors' Rage and the villain Dark Death, mistaking Rage for the villain in the battle. In the weeks that passed, he triumphed over the Rhino in battle and befriended the super-hero the Greenwich Guardian, but he found that super-heroing monopolized his time. When the Greenwich Guardian disappeared during patrol just before Black Death returned, Willis took a break from being Gravity, focusing instead on a relationship with his classmate Lauren Singh.
Later Greg gets sent to Battleworld along with Spider-Man (who later turns out to be Space Phantom), Venom, Henry Pym, Wasp, Medusa, Kraven the Hunter, Firebird, and the Hood. With the help of Dethlok, they discover that it was the Stranger who brought them there to understand humanity. The Stranger allows them to go home, but destorys Battleworld before the group can get back to the ship that brought them there. Gravity holds the planet together so they can make it, but the effort to strong much for him and after making it back toEarth, he dies.
Note: In the divergent reality of Earth-6215, Chronok - a warrior from the future of 2099 A.D. on Earth 6025 – led forces to slaughter the major super-heroes. Gravity joined a group of other minor heroes in traveling forward in time to 2099 and slaying Chronok (and diverging Earth-6025 from Earth-2992) before he could travel back in time. The Earth-616 timeline was thus spared Chronok’s invasion, and Gravity remains a hero in the present day.