▁bless ing , ▁Sweden ▁also ▁under to ok ▁several ▁cr us ades ▁against ▁Orth odox ▁Nov gor od . ▁Many ▁in ▁the ▁East ▁saw ▁the ▁actions ▁of ▁the ▁West ▁in ▁the ▁Mediter rane an ▁as ▁a ▁prime ▁determ ining ▁factor ▁in ▁the ▁weak ening ▁of ▁By z ant ium ▁which ▁led ▁to ▁the ▁emp ire ' s ▁event ual ▁con quest ▁and ▁fall ▁to ▁Islam . ▁ ▁Al big ens ian ▁Cr us ade ▁ ▁The ▁Al big ens ian ▁Cr us ade ▁was ▁launched ▁in ▁ 1 2 0 9 ▁to ▁eliminate ▁the ▁her et ical ▁C ath ars ▁of ▁Occ it ania ▁( the ▁south ▁of ▁modern - day ▁France ). ▁It ▁was ▁a ▁de cade - long ▁struggle ▁that ▁had ▁as ▁much ▁to ▁do ▁with ▁the ▁concerns ▁of ▁northern ▁France ▁to ▁extend ▁its ▁control ▁south wards ▁as ▁it ▁did ▁with ▁her es y . ▁In ▁the ▁end , ▁both ▁the ▁C ath ars ▁and ▁the ▁independence ▁of ▁southern ▁France ▁were ▁ex termin ated . ▁ ▁After ▁a ▁pap al ▁leg ate ▁was ▁murder ed ▁by ▁the ▁C ath ars ▁in ▁ 1 2 0 8 , ▁Pope ▁In noc ent ▁III ▁declared ▁the ▁Al big ens ian ▁Cr us ade . ▁Ab uses ▁committed ▁during ▁the ▁cr us ade ▁caused ▁In noc ent ▁III ▁to ▁inform ally ▁inst itute ▁the ▁first ▁pap al ▁in quisition ▁to ▁prevent ▁future ▁aber r ational ▁practices ▁and ▁to ▁root ▁out ▁the ▁remaining ▁C ath ars . ▁F ormal ized ▁under ▁Pope ▁Gregory ▁IX ,