What is Master Cheif's real name in the hit video-game franchise Halo?

John-117 "Master Chief" is a fictional character and the main protagonist of the Halo fictional universe, created by Bungie. Master Chief is a playable character in the series of science fiction first-person shooter video games: Halo: Combat Evolved, Halo 2, Halo 3, and Halo 4. Outside of video games, the character appears in novels – Halo: The Fall of Reach, Halo: The Flood, Halo: First Strike, and Halo: Uprising – and has cameos in other Halo media, including Halo: Reach, Halo: Ghosts of Onyx, The Halo Graphic Novel, Halo Legends and Halo 4: Forward Unto Dawn.