[1][2][3] Although the Code of Justinian mentions the position of Biarchus as part of the Agentes in Rebus, which were the Imperial couriers,[4] other sources mention their presence in a variety of military positions in the Roman military: they appear in the scholae palatina,[5][6] auxilia palatina,[7] fabricae,[8] vexillationes, and in the stratores.
[14][15][16] It is possible that the Biarchus commanded a contubernium, which was a Roman military unit consisting of ten men.
Speidel states that the Greek etymology of the word exarchus implies the position has eastern roots and potentially originated from new units being created from preexisting horseman and decurions.
Furthermore, the code mandates that if a Biarchus or anyone of a lower rank dies in battle, then their son is obligated to take their place in the army and earn their pay.
[4] One edict issued in the year 534 found in the Code of Justinian directed towards Belisarius outlines the annual payment of eight Biarchi in Africa.