 Abd al-Malik shifted away from his predecessors' use of Arab tribal masses in favor of an organized army.Likewise, Arab noblemen who had derived their power solely through their tribal standing and personal relations with a caliph were gradually replaced with military men who had risen through the ranks.These developments have been partially obscured by the medieval sources due to their continued usage of Arab tribal terminology when referencing the army, such as the names of the tribal confederations Mudar, Rabi'a, Qays and Yaman.