Master Chief Petty Officer John-117, or "Master Chief", is a fictional character and the protagonist of the Halo multimedia franchise. He is a SPARTAN-II commando of the UNSC Naval Special Warfare Command. He is the protagonist and main character in both the Halo trilogy and Reclaimer Saga. With over thirty years of active duty, he has become one of the most decorated war veterans in the United Nations Space Command, earning every known UNSC medal except the Prisoner of War Medallion.