The Ahto conflict occurred not long before the Battle of Endor, and is classified as a battle.
Following more than ten years of occupying Manaan, the Galactic Empire became negligent with its forces stationed in Ahto City. Darth Vader arrived on the planet prior to the scheduled troop rotation and engaged with members of the Order of Shasa. The Shasans, under the impression that he was a Jedi, heeded his instructions regarding troop movements and his strategy for defeating them.
Empowered by the dark side, a group of two hundred Shasans infiltrated Ahto City via the sewer system. They caught the ill-prepared guards off guard, eliminating many. The remaining Imperial troops withdrew from the world. Initially, the Shasans intended to allow the patrons of Ahto Luxury Resorts to depart unharmed, but influenced again by the dark side, they proceeded to slaughter them.
Vader subsequently convened with the Order, revealing the destruction of the Jedi Order and declaring their allegiance to his own master.
Fewash Welko later documented the events of the battle in his publication, The Battle of Ahto: A Memoir.