John-117

''“Do not underestimate them. But most of all, do not underestimate him.” ''--Dr. Catherine Halsey, Halo 4

Master Chief Petty Officer John-117, or more commonly known as the Master Chief, is a Spartan-II Commando of the UNSC Naval Special Warfare Command who became one of the most important UNSC heroes during the Human-Covenant War.   With over thirty years of active duty, he has become one of the most decorated war veterans in the  United Nations Space Command, commonly referred as the UNSC,  earning every known UNSC medal except the  Prisoner of War Medallion.