Halo is set several centuries in the future. After the development of the "Shaw-Fujikawa Translight Engine", the United Nations Space Command (UNSC) begins a program of interstellar travel and planetary colonization. Over 800 planets are colonized in 200 years, categorized as "Inner Colonies" and "Outer Colonies". The Inner Colonies, being closer to Earth, are more developed and politically stable. The Outer Colonies were reachable after the breakthrough of the Shaw-Fujikawa Translight Engine. Due to the older planets' need for the raw materials and supplies the Outer Colonies provide, tensions and outright civil war foments between the colonies and the UNSC. The UNSC creates the SPARTAN-II Project in order to covertly suppress these rebellions. Twenty-seven years before the events of the main game trilogy, UNSC communication with the colony Harvest is lost, and the ship sent to investigate is destroyed by the Covenant, a theocratic collective of aliens bent on exterminating humanity.The Covenant leadership has declared humanity to be an affront to their gods, the Forerunner. By 2535, almost all of the Outer Colonies have been destroyed by the Covenant; in response, the UNSC vigorously enforces the "Cole Protocol", destroying material and ships that might lead the Covenant to Earth. The Covenant possesses a significant technological advantage, and proves nearly impossible for the UNSC to defeat in space engagements. These events are only alluded to in the video games, but their full descriptions are outlined in the novels Halo: The Fall of Reach and Contact Harvest, as well as in the real-time strategy game Halo Wars.