Len Duok was a Jedi Master during the conflict that took place directly after the Grand Sith Purge. He was good friends of Master Kaan, Master Ayeel, Master Ventar, Master Glace, and Master Donin. He trained along with Kaan and helped each other get through the training easier than they would have alone. He and Master Kaan were seen as very wise for their age and showed great potential. He became a Jedi Master and would train a young Jedi named Alno Doon. His apprentice would eventually fall to the dark side and would return for his master, only to fight him. Duok refused to fight and was murdered by hi old apprentice.