Skopje was a UEG inner colony and the home to several million people. The colony was first mentioned during the Human-Covenant war, when it was glassed by the Covenant in 2547 after a large battle that took place there.
The planet had highly developed urban areas, roads, and railways sprawled across island continents. It was also home to the headquarters of a shipbuilding corporation. Orbital Drop Shock Troopers were called in to defend the headquarters during the evacuation of their shipyards, under the justification that the machines, tools, and personnel that could be saved would be relocated to Reach to continue building parts for the war effort. A wealthy CEO built a castle in the colony, which would later prove valuable during the battle.