The Battle of Sector 3123 was a battle of the Galactic Civil War that occurred in Sector 3123. It came about when the Rebel Alliance learned of an important Imperial research facility in the fringes of a nebula within that sector, and hence launched a lightning attack to take it out. However, rebel intelligence greatly underestimated Imperial defences and hence most of the alliance taskforce was decimated upon arrival. After the battle, the transport containing the 12th Alliance Specforce team was missing, along with an Imperial cruiser containing its rival, the 888th Imperial Legion. Both were registered as 'missing in action'.
A short while before the battle, Bothan spies leaked information to the rebellion about the Imperial facility in the nebula, where some of the Death Star components had been manufactured. Crix Madine immediately decreed that the facility needed to be eliminated. The Bothans believed that the facility would be lightly defended due to the nebula interference. Immediately, a small fleet was mustered, and a segment of the 12th Alliance SpecForce team was assigned to board the station.