Emmer, which was initially called Umhul when it was a component of Xim's empire, existed as a high-gravity planet within the Nilgaard sector, characterized by its luminous grasslands and extensive cityscapes. Before 45 BBY, this planet became a member of the Galactic Republic. The Emmerian walker vehicles served as an inspiration for constructions by Kuat Drive Yards, for example, the AT-AT.
By 4 ABY, the planet had transformed into an Imperial fortress world. In the aftermath of the Battle of Endor, Mon Calamari who sided with the New Republic succeeded in defeating the Imperial presence there. Nevertheless, Warlord Zsinj subsequently gained control of the world. The New Republic then freed the planet during the Post–Zsinj campaigns in 8.5 ABY.