During the Battle of Sigma Octanus IV in 2552, the base was set up near Cote D'Azur so that the Marines, under the command of General Kits, could assault the city, which had been captured by the Covenant.
The Covenants attacked with Wraith tanks, Banshee fliers, and thousands of Unggoy. The Marines were able to hold them off, but at a heavy cost, almost the entire base was destroyed, and only ten Marines survived the incident. When a single Warthog with Corporal Harland arrived, he assumed tactical command of the entire ground operation.
Harland was quickly relieved by a team of Spartan-IIs once they landed their Pelican in the base and used it as a staging area. They successfully killed all the Covenant soldiers in the area with a HAVOK tactical nuclear device, destroying Cote D'Azur and the remains of Alpha Headquarters consequently.
The base was staffed by 400 Marines when it came under assault by the Covenant forces.