Origin
Uranus was created by the Celestials one million years ago along with the first generation Eternals. He believed Eternals superiority granted rights conquer the Earth but his brother Kronos disagreed. After his rebellion was stopped by Kronos, him and his remaining followers were exiled into space.
The Exclusion
After the Eternals self-destroyed and resurrected themselves, Uranos was also resurrected then confined the Exclusion for his crimes.