At some point before the Battle of Vrogas Vas the Alliance to Restore the Republic established a secret refueling base as their base of operations on the planet Vrogas Vas. The base was discovered by the Galactic Empire when the Sith Lord Darth Vader attacked and destroyed two of the three X-wing squadrons protecting the base and crashed onto the planet's surface along with Luke Skywalker. The rebels then attempted to kill Vader with a large number of troops and tanks but Vader out-witted them by detonating their grenades using the Force. Vader also obliterated two Y-wing squadrons until Commander Karbin and his forces took over forcing the rebels to retreat. Vader then killed Karbin and before he could get his hands on Skywalker he escaped.