te ▁when ▁the ▁pap acy ▁found ▁it ▁necessary ▁to ▁return ▁to ▁Rome . ▁The ▁hope ▁of ▁re unit ing ▁Latin ▁and ▁Orth odox ▁Christians , ▁along ▁with ▁the ▁achiev ement ▁of ▁peace ▁in ▁the ▁Pap al ▁States ▁in ▁Italy , ▁made ▁the ▁case ▁of ▁returning ▁stronger . ▁Added ▁to ▁that ▁was ▁the ▁strong ▁conv iction ▁of ▁both ▁Urban ▁V ▁and ▁Gregory ▁XI ▁that ▁the ▁seat ▁of ▁the ▁pap acy ▁could ▁only ▁be ▁the ▁tomb ▁of ▁St ▁Peter . ▁Despite ▁strong ▁opposition ▁from ▁the ▁Court ▁of ▁France ▁and ▁the ▁College ▁of ▁Card inals , ▁both ▁pop es ▁found ▁the ▁means ▁to ▁return ▁to ▁Rome , ▁the ▁first , ▁on ▁ 3 0 ▁April ▁ 1 3 6 2 , ▁the ▁second ▁on ▁ 1 3 ▁September ▁ 1 3 7 0 . ▁This ▁time , ▁the ▁return ▁was ▁absolute . ▁ ▁In ▁the ▁following ▁centuries , ▁the ▁Pal ais ▁lost ▁all ▁of ▁its ▁former ▁glory , ▁despite ▁serving ▁as ▁the ▁seat ▁of ▁two ▁anti - pop es ▁and ▁many ▁card inals . ▁It ▁retained , ▁however , ▁a ▁“ work ▁of ▁destruction ” ▁aspect ▁that ▁French ▁po ets ▁and ▁writers ▁such ▁as ▁Charles ▁For bes ▁René ▁de ▁Mont alem bert ▁have ▁referred ▁to ▁over ▁the ▁centuries , ▁with ▁its ▁powerful ▁sense ▁of ▁beauty , ▁simplicity , ▁grande ur ▁and ▁imm ort ality . ▁ ▁Since ▁ 1 9 9 5 , ▁the ▁Pal ais ▁des ▁Pap es ▁has ▁been ▁class ified , ▁along ▁with ▁the ▁historic ▁center ▁of ▁Av ignon , ▁as ▁a ▁UN