The campaign of Halo Wars begins in the year 2531.
Halo Wars is a real-time strategy game developed by Ensemble Studios and published by Microsoft Game Studios for Xbox 360. Its story is set 21 years before the events of Halo: Combat Evolved, placing its opening conflicts in 2531 during the Human-Covenant War.
The game follows the crew and forces of the UNSC Spirit of Fire. The ship responds to Covenant activity on the human colony of Harvest and later investigates ancient Forerunner technology. The campaign introduces a separate group of human and Covenant characters rather than retelling Master Chief’s original trilogy storyline.
The year is easy to mix up with 2525, which marks the beginning of the Human-Covenant War in established Halo chronology. It is also earlier than the 2552 setting of the first mainline Halo games. Halo Wars 2 continues the Spirit of Fire’s story much later, after the ship’s crew encounters the Banished at the Ark.