The Battle of New Constantinople was a major engagement between UNSC and Covenant forces That occured some time in late 2536 or early 2537.
Admiral Danforth Whitcomb distinguished himself in that battle and was awarded several decorations for his actions. Unfortunately, the battle was lost and the Covenant destroyed the planet.
Spartan-III Alpha Company fought in the engagement well, and they were highly distignuished for their actions during the battle.