Dieben was a male Nalydian criminal who was wanted for various crimes on his homeworld of Nalyd. He was regarded by Ania Solo as unintelligent and lacking much imagination at lying. By 138 ABY, Dieben had come into the services of the rogue Sith Darth Wredd, who had broken away from the underground One Sith order. During the Carreras Incident in 138 ABY, Dieben was placed in charged of guarding the captured Imperial Knight Yalta Val, who was imprisoned on the floating dead world of Mala. His known duties included providing food to the imprisoned Val and facilitating communications between Wredd and his captive. Meanwhile, his master Darth Wredd impersonated the real Yalta Val and took charge of the assembly of the Carreras G51 communications array.