It is possible they fought in the
Battle of the Milvian Bridge for Emperor
Constantine I (312). This assumption is based on the fact that Constantine had possibly had them portrayed on his
triumphal arch in Rome. In the 4th century, the
Petulantes were in the army of the emperor
Julian. The unit amounted to 500 men, but, in order to obtain a tactically valid unit, they were often united with the
Celtae. As part of Julian's army, the
Petulantes took part in the victorious
Battle of Strasbourg (357). When Julian, camped in
Lutetia, received the order from his cousin the Emperor
Constantius II to send some troops (including the
Petulantes) to the east, the troops revolted, because Julian had promised to keep them near their families. One of the standard-bearers of the
Petulantes, Maurus, put the crown on Julian's head, proclaiming him
Augustus (361). Together with the
Celtae, the
Petulantes fought against the
Alamanni near
Sanctium, in
Raetia. In 365, the
Augustus Senior of the west,
Valentinian I, and the
Augustus Iunior of the east,
Valens, divided the army in two parts, and it is possible that in this occasion the
Petulantes were divided into two units, the
seniores and the
iuniores. The
Notitia Dignitatum, an early-5th century document, lists the
Petulantes seniores among the
auxilia palatina, the elite units, under the command of the
magister peditum of the west. The same document gives the
Petulantes iuniores under the command of the
magister militum per Illyricum, with a different shield pattern. == Notes==