The first one are mercenary ethnic detachments composed of the Germans. As anybody knows, Constantine I managed some military campaigns at the Rhine frontier against the German tribes, but Constantine I also signed treaties with some of these tribes about the military assistance and alliances from the part of the Germans in favor of the Romans. According to these treaties, the Germans sent its military retinues in army of Constantine I, their service was paid by money and as a result of this they occupied a privileged place within Constantine's army.

The second one were regular vexillations levied from internal (local) citizens of Empire, mainly from the populace of Gaul. First of all, inscriptions mention about a vexillation detached from the legio II Italica, this vexillation quartered in the fortress ofDivitia, within modern Köln, and was namedDivitenses after the place of its garrison. Apart fromDivitenses, Constantine I commanded over the vexillation of legio IV Flavia (the legion itself located in upper Moesia), a mailed cavalry, Dalmatian cavalry and two self-sufficient legions, that areloviani иHerculiani, they had stood in Gaul since the first Tetrarchy. Latin panegyrics report that the strength of Constantine's army was nearly 40 000 men.

Among Constantine's vexillations were also two units of mailed cavalry from Poitiers and Amiens and vexillation entitled asUrsarienses after a name of the city ofUrsaria, which located in the Gallic province ofMaxima Sequanorum (at the south-east of Gaul, near to borders between Italia and Raetia).

All vexillations enumerated above were sent from Gaul in Western Illyricum in 316 for to fight against Licinius. Therefore, an army of Constantine I arrived in Western Illyricum and then located there from 316 to 324 (precisely in Pannonian provinces, Upper Moesia and, possibly, in Dalmatia). Afterwards, in 324, when Constantine I decisively won over Licinius, this military group with its full strength advanced down to Lower Danube, in Thrace, which was a place for battles between Constantine I and Licinius.

However, during the second Tetrarchy, in 305–324, military reforms touched upon not only Balkan areas, but also the Near East regions. As we suppose, Maximinus II Daia, Caesar and then a self-proclaimed Augustus, who reigned in Eastern provinces of Empire during 305–313, managed a vast reform, which resulted to an establishment of a self-sufficient and single province of Minor Armenia and creation of a new office, that is dux of Minor Armenia, this reform enabled Maximinus to reinforce a defence of the Near East front from Persian invasions. The evidence of many hagiographie texts gave us a chance to maintain that Maximinus managed his reform during 305–312, a territory of Minor Armenia was singled out of Cappadocia and modified into a self-sufficient province, the head of this province was a special military official, we mean dux, so, three powerful legions stood under his supervision, that are XV Apollinaris, XII Fulminata and I Pontica.