Akdor was the name of the third planet in the Sh'lassen Triumvirate, with the inhabitants locked in a deadly civil war. Located in Sector 21, the planet was strategically close to Narn and Centauri space. 
A heavily defended fortress on Akdor, used by Sh'lassen rebels as their main stronghold. John Sheridan had previously visited Matok as part of the Kurani Expedition, later describing it as less a fortress than a deathtrap. As a part of an agreement between the Earth Alliance and the Sh'lassen government in 2259, Earthforce sent the 356th Infantry Division under the command of General Richard Franklin to take Matok as a part of Operation Sudden Death. Following a heavy assault, Matok fell to Earthforce troops, with virtually all of the rebel leaders either captured or killed. The victory came at a price, as the infantry suffered heavy casualties.