Editing Constantius II (section)

===Usurpation of Julian and crises in the east===
[[File:The triumph of Constantius II.jpg|thumb|270px|Missorium of Kerch depicting Constantius II on horseback with a spear. He is preceded by victory and accompanied by a guardsman ([[Hermitage Museum]]).]]
In the meantime, Julian had won some victories against the [[Alamanni]], who had once again invaded [[Roman Gaul]]. However, when Constantius requested reinforcements from Julian's army for the eastern campaign, the Gallic legions revolted and proclaimed Julian ''augustus''.{{sfn|Drinkwater|2007|p=253}}{{sfn|Potter|2004|p=505}}{{sfn|Hunt|1998|p=57}}{{efn|Ammianus and Julian both portrayed Constantius's order as fueled by envy of the Caesar’s growing popularity, with the additional intent of weakening his military position, as he had previously done with Gallus.<ref>Walter E. Roberts and Michael DiMaio Jr., [http://www.roman-emperors.sites.luc.edu/julian.htm Julian (361–363 A.D.)] {{Webarchive|url=https://web.archive.org/web/20230924080550/http://roman-emperors.sites.luc.edu/julian.htm |date=24 September 2023 }}</ref> Crawford was skeptical of such a portrayal, believing that Julian would’ve needed far less troops than Constantius if he was really as successful as he portrayed himself,{{sfn|Crawford|2016|p=212}} while Potter dismissed the idea, believing that the necessity of Constantius's act for his plan was sufficient explanation.{{sfn|Potter|2004|p=505}}}}

On account of the immediate Sassanid threat, Constantius was unable to directly respond to his cousin's usurpation, other than by sending missives in which he tried to convince Julian to resign the title of ''augustus'' and be satisfied with that of ''caesar''. By 361, Constantius saw no alternative but to face the usurper with force, and yet the threat of the [[Sassanid Empire|Sassanids]] remained. Constantius had already spent part of early 361 unsuccessfully attempting to re-take the fortress of Ad Tigris.<ref>[[Ammianus Marcellinus]], ''Res Gestae'' XX.11.6–25</ref> After a time he had withdrawn to [[Antioch]] to regroup and prepare for a confrontation with [[Shapur II]].<ref>[[Ammianus Marcellinus]], ''Res Gestae'' XXI.7.7 & 13.1–5</ref> The campaigns of the previous year had inflicted heavy losses on the Sassanids, however, and they did not attempt another round of campaigns that year. This temporary respite in hostilities allowed Constantius to turn his full attention to facing Julian.{{sfn|Vagi|2001|p=508}}