Magister militum ("Master of the Soldiers") was a rank used in the later Roman Empire dating from the reign of Constantine. Used alone, it refers to the senior military officer and (equivalent to a shogun or generalissimo) of the Empire. The Magister Militum was usually the power behind the throne and was held by Stilicho, Ricimer, Odoacer and others.
It was also often used with a provincial name, such as the Magister militum per Thracias ("Master of the Soldiers of Thrace"), to indicate the commanding general of a region.
Compare the usage "patricius" in the Late Empire.
