The magister militum was the master general of the Roman field army, a post that emerged in the late 4th and early 5th centuries AD as the Western Roman Empire came under increasing pressure from the Germanic tribes along its borders, and it became necessary to have a single military authority to deal with the crisis.

Historically speaking the two most important holders of this appointment were, Flavius Stilicho who was held the post under the emperor Honorius and Flavius Aetius who served under Valentian III.

Such was the scope of their authority and the potential for political power inherent in the appointment, that their influence on events was often greater than that of their nominal masters. The greater their success in maintaining the authority of Rome in the west, the greater the threat they appeared to become to the established imperial administration. It is no coincidence that both Stilicho and Aetius were eventually murdered at the order of the very emperors that they served.

Holders of the Title of Magister Militum