Allyuen, situated within the Anoat sector of the Outer Rim Territories in the galaxy, was a planet. The Galactic Empire maintained a garrison at the Allyuen spaceport located there.
While the Empire enacted the Iron Blockade to keep news of their devastating loss to the Alliance to Restore the Republic at the Battle of Endor from the people living in the Anoat sector, someone unidentified on Allyuen transmitted a distress signal on a seldom-used channel, seeking both medical support and a way off-world. The Smuggler dispatched a member of their crew to Allyuen in order to provide assistance upon receiving this plea.
The radio adaptation of Star Wars: Episode V The Empire Strikes Back provided the initial reference to Allyuen. Its inclusion in the action role-playing game Star Wars: Uprising, created by Kabam for iOS and Android and launched on September 10, 2015, established it as canon.