▁in ▁his ▁northern ▁campaign s ▁between ▁ 1 6 9 – 1 7 5 ▁and ▁ 1 7 8 – 1 8 0 . ▁Two ▁pre fect s ▁were ▁killed ▁during ▁these ▁exped itions . ▁ ▁With ▁the ▁acc ession ▁of ▁Com mod us , ▁in ▁ 1 8 0 , ▁the ▁Pra et or ian ▁Guard ▁returned ▁to ▁Rome . ▁Tig id ius ▁Per ennis ▁( AD ▁ 1 8 2 – 1 8 5 ) ▁and ▁fre ed man ▁Marcus ▁A ure lius ▁Cle ander ▁( AD ▁ 1 8 6 – 1 9 0 ) ▁exerc ised ▁considerable ▁influence ▁on ▁the ▁em peror . ▁Per ennis ▁was ▁killed ▁by ▁a ▁deleg ation ▁of ▁ 1 5 0 0 ▁persons ▁of ▁Great ▁Britain ▁which ▁came ▁forth ▁to ▁comp lain ▁about ▁his ▁inter ference ▁in ▁the ▁affairs ▁of ▁the ▁province ▁( a ▁deleg ation ▁of ▁L anci ari i ▁of ▁the ▁ 3 ▁leg ions ▁of ▁Great ▁Britain ). ▁Cle ander ▁ab used ▁his ▁influence ▁to ▁nomin ate ▁and ▁dismiss ▁pre fect s . ▁ ▁In ▁ 1 8 8 , ▁Cle ander ▁obtained ▁the ▁joint ▁command ▁of ▁the ▁Guard ▁with ▁the ▁two ▁pre fect s . ▁Cle ander ▁ordered ▁a ▁mass acre ▁of ▁civ ili ans ▁carried ▁by ▁the ▁equ ites ▁singular es ▁August i ▁which ▁led ▁to ▁an ▁arranged ▁battle ▁with ▁the ▁Urban ▁C oh ort s . ▁ ▁Sever an ▁dynast y ▁ ▁Com mod us ▁fell ▁victim ▁to ▁a ▁consp i racy ▁directed ▁by ▁his ▁Pra et or