The Battle of Durisdeer, occurring in June 2531, was an engagement during the Human-Covenant War above the colony world of Durisdeer. The UNSC Navy's nine vessels, in the face of superior numbers, sought to hold off the Covenant invasion long enough for Durisdeer's population to escape. However, in a brief exchange of fire, the UNSC fleet of nine warships was annihilated for two Covenant CCS-class battlecruisers destroyed. The remaining Covenant vessels then moved in to glass the world and its undefended inhabitants.