The Vulpinus Nebula existed as a nebula within the Expansion Region of the galaxy.
Galactic Emperor Sheev Palpatine dispatched Admiral Gallius Rax to the Vulpinus Nebula on the Super Star Destroyer Ravager a short time before the Battle of Endor. Following the Rebellion on Akiva, Rax continued to be based in the Vulpinus Nebula, having since been elevated to the rank of Imperial Fleet Admiral.
The Vulpinus Nebula became a haven for a large Imperial fleet by 5 ABY. This fleet was under the nominal command of Grand Admiral Rae Sloane, who was essentially a puppet for Rax. The inaugural Shadow Council meeting was held by Rax and Sloane within the Vulpinus Nebula.
Following the attack on Chandrila, Rax assumed direct command of the Imperial fleet stationed in the Vulpinus Nebula. He then directed it, along with the other Imperial fleets under his authority, to converge above the planet Jakku for a showdown against the New Republic. After the fall of the Galactic Empire, Imperial survivors would utilize the Vulpinus Nebula as a sanctuary.