The structure and organization of mobile army of the Emperor Gallienus in 260 – 268

Abstract

In the middle of the III century, the Roman Empire marked the advent of a prolonged crisis. In order to confront the barbarian invasions and usurpers revolt, military transformations, the Roman Empire was in needed for military transformations and revision of the military machine that has formed in the previous periods. In the late 250s – early 260s, the Emperor Gallienus created a mobile army corps, which in the ancient sources received a name of the “Dalmatian horsemen”. The following questions arise on the structure and size of this mobile corps. Relying on numismatic, narrative, and epigraphic sources, this article examines the changes in organizational and staffing structure of the Roman army in the middle of the III century; assesses the size and composition, and tasks of the Gallienus’ mobile corps. The author analyzes the opinions that have accumulated in the Russian and foreign historiography throughout 200 years, and develops a relevant perspective on the problem of creating a field army during the third century crisis.  The conclusion is made that the Emperor Gallienus had formed a strong mobile army. It was not just a cavalry, but was based on the vexilationes of the border legions of infantry and horsemen. Gallienus did not seek to create a permanent mobile army, being guided by the prevailing military and political circumstances. He used the mobile corps for retaining the controlled territories, repelled the barbarian invasions and suppressed the usurpers. Gallienus’ mobile army has proven to be an effective instrument in hands of the central government. Aurelian reinforced the army with additional detachments, and later on successfully used it against Palmyrene and Gallic separatists, having restored the unity of the empire.