▁A ▁smaller ▁stone ▁fort ification ▁was ▁built ▁inside ▁these ▁r amp arts ▁and ▁this ▁contained ▁a ▁palace ▁and ▁buildings ▁belonging ▁to ▁the ▁arist ocracy . ▁ ▁While ▁Pl iska ▁experienced ▁nearly ▁a ▁century ▁of ▁growth ▁following ▁its ▁selection ▁as ▁the ▁capital ▁of ▁the ▁new ▁Bulgar ian ▁state , ▁this ▁was ▁not ▁a ▁peace ful ▁era . ▁ ▁The ▁Bulg ars ▁and ▁By z antine ▁Empire ▁were ▁in ▁an ▁almost ▁constant ▁state ▁of ▁war ▁during ▁the ▁e ighth ▁century ▁and ▁into ▁the ▁early ▁nin th . ▁Emperor ▁Const antine ▁V ▁o vers aw ▁nine ▁campaign s ▁against ▁the ▁Bulg ars ▁between ▁ 7 4 1 ▁and ▁ 7 7 5 , ▁and ▁Emperor ▁N ike ph or os ▁I ' s ▁campaign ▁in ▁ 8 1 1 ▁resulted ▁in ▁the ▁burning ▁of ▁the ▁royal ▁residence ▁in ▁Pl iska . ▁In ▁this ▁last ▁instance ▁the ▁em peror ▁led ▁a ▁massive ▁army ▁to ▁Pl iska ▁in ▁ret ali ation ▁for ▁the ▁Bulgar ian ▁capture ▁of ▁S ard ika ▁and ▁mass acre ▁of ▁its ▁g arrison ▁that ▁occurred ▁in ▁an ▁earlier ▁set ▁of ▁host ilities . ▁The ▁Bulgar ian ▁leader ▁K rum ▁was ▁not ▁prepared ▁to ▁face ▁the ▁em peror ' s ▁army ▁and ▁thus ▁abandoned ▁Pl iska ▁and ▁the ▁By z ant ines ▁pl under ed ▁the ▁palace ▁and ▁town ▁there ▁and ▁burn ed ▁it ▁to ▁the ▁ground ▁as ▁it ▁was ▁largely ▁at ▁this ▁time ▁made ▁of ▁wood . ▁So on ▁after , ▁the ▁inv aders ▁were ▁driven ▁out ▁by ▁Khan ▁K rum ▁( see ▁Battle