Death Watch commander Pre Vizsla built a massive military operation during the Clone Wars, including secret bases spread throughout the galaxy. One such outpost was Vizsla Keep 09, which was hidden in the rings of Phelbos. Darth Maul, who’d assumed control of Mandalore after defeating Vizsla in combat, knew of the fort. During the Clone Wars, he brought Count Dooku and General Grievous to the Keep after capturing them on Ord Mantell; the Republic later tracked Maul there, leading to a battle between clones and Maul's Shadow Collective. Years later, Maul used it as a meeting point with the Ghost rebels, where he would join Sith and Jedi holocrons together to gain secret knowledge.