Contibutory Info: Halo
The most comprehensive resource I found for information about Halo was wikipedia. Providing extensive information about the series storyline, development, and even cultural impact, the current wikipedia Halo entry states that the Halo series “centers on an interstellar war between humanity and a theocratic alliance of aliens known as the Covenant.
It continues, “The Covenant worship an ancient civilization known as the Forerunners, who perished in combat with the parasitic Flood. Many of the games center on the experiences of Master Chief John-117, a cybernetically-enhanced human super-soldier, and his artificial intelligence (AI) companion, Cortana.”