b ish ops ▁of ▁C ologne , ▁T rier , ▁Main z ▁and ▁Mag de burg . ▁ ▁The ▁Count s ▁of ▁Kat zen eln b ogen ▁are ▁also ▁govern ors ▁of ▁the ▁Ab bey ▁of ▁Pr ü m ▁and ▁this ▁allow ▁them ▁to ▁establish ▁their ▁own ▁territory ▁around ▁their ▁seat ▁Burg ▁R he inf els ▁Castle ▁in ▁St . ▁Go ar . ▁ ▁When ▁the ▁male ▁line ▁of ▁the ▁Count s ▁dies ▁out ▁in ▁ 1 4 7 9 , ▁this ▁territory ▁is ▁inherited ▁by ▁the ▁Land gra ves ▁of ▁H esse . ▁ ▁The ▁grands ons ▁of ▁Char lemagne ▁split ▁his ▁Empire ▁in ▁the ▁Tre aty ▁of ▁Verd un ▁of ▁ 8 4 3 , ▁which ▁they ▁prepared ▁in ▁the ▁Bas il ica ▁of ▁St . ▁Cast or ▁in ▁Kob len z ▁in ▁ 8 4 2 . ▁ ▁The ▁left ▁bank ▁of ▁the ▁Rh ine ▁between ▁Bach ar ach ▁and ▁Kob len z ▁falls ▁to ▁Middle ▁Francia . ▁ ▁In ▁ 9 2 5 , ▁Middle ▁Francia ▁is ▁finally ▁becomes ▁the ▁Duch y ▁of ▁Lor raine ▁within ▁East ▁Francia , ▁the ▁German ▁Empire . ▁ ▁The ▁Rh ine ▁remains ▁the ▁heart land ▁of ▁the ▁royal ▁power , ▁or ▁ ▁as ▁Otto ▁of ▁Fre ising ▁called ▁it , ▁until ▁in ▁ 1 1 3 8 ▁Con rad ▁III ▁is ▁elected ▁King ▁of ▁Germany ▁in ▁Kob len z , ▁the ▁first ▁King ▁of ▁the ▁House ▁of ▁H ohen st auf en . ▁ ▁Late ▁Middle ▁A ges ▁▁ ▁The ▁late ▁Middle ▁A