Operation FROSTY PEAK, known colloquially as the Battle of the Sigma Bangaa System, was a brief conflict that occurred during early 2631 in the Sigma Bangaa System. It was the first notable battle between UNSC and Insurrectionist forces in nearly forty years mostly due to the successive Second Great War and War of 2626. During this hiatus, Insurrectionists were able to gain multiple footholds within and outside the Human Sphere, a number of them lying within the Σ Bangaa System. Before long, the UNSC deployed the freshly assembled Battlegroup Murmillo and later advanced stealth cruiser to combat the die-hard rebels in the system.