At the beginning of the Kree-Skrull War, millions of years ago in Earth time, the alien Kree established a station on the planet Uranus, a strategic position between the Kree and Skrull empires. Through their work at this station, they discovered that sentient life on nearby Earth had genetic potential invested in it by the alien Celestials. Intrigued, the Kree began to experiment on Earth's then-primitive Homo Sapiens by splicing Arlok's DNA into Cro-Magnons. Arlok was an Eternal who was a follower of Uranos that had been dissected by the Kree.