▁began ▁his ▁military ▁career ▁under ▁Anton inus ▁P ius , ▁rising ▁to ▁the ▁status ▁of ▁leg atus . ▁He ▁served ▁during ▁the ▁Par th ian ▁War ▁of ▁Lu cius ▁Ver us , ▁in ▁which ▁he ▁distinguished ▁himself , ▁for ▁which ▁he ▁was ▁elev ated ▁to ▁the ▁Senate , ▁and ▁later ▁made ▁Imperial ▁leg ate . ▁During ▁the ▁Bu col ic ▁War , ▁he ▁was ▁given ▁the ▁extraordinary ▁title ▁of ▁R ector ▁Orient is , ▁giving ▁him ▁Imper ium ▁over ▁all ▁of ▁the ▁eastern ▁provinces ▁of ▁the ▁Roman ▁Empire . ▁▁ ▁In ▁ 1 7 5 AD , ▁Cass ius ▁declared ▁himself ▁em peror , ▁because ▁he ▁had ▁received ▁news , ▁from ▁Marcus ▁A ure lius ' ▁wife , ▁that ▁the ▁Emperor ▁Marcus ▁A ure lius ▁was ▁about ▁to ▁die . ▁He ▁received ▁broad ▁support ▁in ▁the ▁eastern ▁provinces ▁of ▁Egypt , ▁Sy ria , ▁Sy ria ▁Pala est ina ▁and ▁Arab ia ▁Pet ra ea , ▁especially ▁Sy ria , ▁which ▁was ▁his ▁hom eland . ▁Despite ▁his ▁control ▁of ▁the ▁vital ▁gra in ▁production ▁of ▁Egypt , ▁and ▁his ▁command ▁of ▁seven ▁leg ions , ▁he ▁was ▁heavily ▁out match ed ▁by ▁A ure lius . ▁While ▁A ure lius ▁was ▁am ass ing ▁a ▁force ▁to ▁defeat ▁Cass ius , ▁a ▁cent ur ion ▁of ▁one ▁of ▁Cass ius ' ▁leg ions ▁murder ed ▁Cass ius , ▁sending ▁his ▁head ▁to ▁A ure lius ▁as ▁proof . ▁ ▁Early ▁life ▁Av id ius ▁Cass ius ▁was ▁born ▁around ▁ 1 3