In sum, to the late of 350 Constantius II commanded over three military bodies (groups), the first one were units moved from the Near East front, the second one were legions and vexillations of the Danube army ofcomitatenses and the third one were the frontier garrisons of the Western Illyricum.

According to Iohannes Zonaras, the whole effective of Constantius Il's troops was 80 000 men, and Magnentius' troops numbered nearly 36 000, a decisive battle happened in September of 351 at the city of Mursa in Pannonia, the losses were 30 000 from Constantius II and 24 000 from Magnentius, this battle was successful for Constantius II.

Primarily, we have to point out that Magnentius' army included two kind of troops, that were mercenary units levied from the Franks and the Saxons and regular legions which stood at the Rhine frontier. Epigraphy data helped us to distinguish among these regular Rhine regiments the units ofHerculiani, loviani andMoesiaci. To our point of view, these regiments didn't participate in the battle at Mursa because Magnentius preferred to stay them in Northern Italy, where they served as the integral parts of a usurper's personal palace bodyguard.

When Constantius II returned to himself a power over the Northern Italia in September of 352, he didn't disband these elite regiments, but, in contrast, the victorious Emperor preferred to include them in its own army. We think that strictly in that time, around 352–353, Constantius II took and managed an important reform of conscription system for completion the army, this reform generated a vast number of new military detachments entitled asseniores andiuniores. All survived epigraphy data and evidence of narrative sources enabled us to trace that Constantius II firstly included in his army the regiments ofHerculiani, loviani, and also units ofMoesiaci andequites Cornuti and then he implemented them with the groups of new recruits.

Little time after Constantius II singled out these groups of recruits and modified them into self-sufficient units, which received an additional nickname ofiuniores, i. e. «the juniors», precisely,Herculiani iuniores, loviani iuniores, Moesiaci iuniores andequites Cornuti iuniores. At the same time, the old «paternal» units, which saved their original staff and which were deprived of new recruits, received an additional nickname ofseniores, «the seniors», that wereHerculiani seniores, loviani seniores, Moesiaci seniores andequites Cornuti seniores. The main ground of om arguments was an anonymous military treaty conventionally entitled asDe rebus bellicis.