Battle of Durisdeer

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 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 destroyed. The remaining Covenant vessels then moved in to glass the world and its undefended inhabitants. 
The sole surviving UNSC vessel, the destroyer Resurgence (DDG-409), retreated to the planet's atmosphere while the eleven Covenant ships advanced on the planet. This retreat went unnoticed due to the abundance of debris from defeated UNSC vessels dispersing in orbit. Here it served as command for the ongoing evacuation effort until the Covenant entered orbit, at which time it retreated to a mountainous region near the south pole. Forty minutes later, a CCS-class battlecruiser passed within a kilometre of where Resurgence lay in a state of minimal power. As she rose to escape the planet, Resurgence managed to destroy the enemy ship with two MAC rounds to its unshielded energy projector. With the rest of the Covenant vessels dispersed across the planet in glassing formation, Resurgence managed to escape and, in the confusion she caused, a further two civilian transports made it to orbit and slipspace, ultimately comprising 30% of all survivors from the colony.
With no organised resistance remaining, the Covenant completed glassing the planet's urban areas. Roughly 30% of the colony's population of 150,000 had yet to escape the surface, or were intercepted and destroyed in the attempt to leave the system. Though the battle was a tactical and strategic defeat, Resurgence was awarded a battle honour for her courageous resistance, and her captain received the Legion of Honour for his actions.