Formerly an architect, social activist, and U.S. Marine sniper, John Stewart was chosen by the Guardians of the Universe to join the Green Lantern Corps, an intergalactic peacekeeping organization dedicated to protecting life throughout the universe. Stewart has proven himself time and again to be an exceptional champion in countless missions that have taken him across the cosmos. His distinguished service in the Corps has resulted in a place among the Oan Honor Guard and the position of Corps Leader.