▁and ▁def ences ▁of ▁Quebec ▁is ▁due ▁to ▁the ▁inter vention ▁of ▁Governor ▁General ▁of ▁Canada ▁the ▁Mar qu ess ▁of ▁D uffer in ▁and ▁A va , ▁who ▁also ▁established ▁the ▁Cit ad elle ▁as ▁a ▁vic er eg al ▁residence ▁in ▁ 1 8 7 2 , ▁rev iving ▁a ▁tradition ▁d ating ▁to ▁the ▁found ing ▁of ▁New ▁France . ▁Since ▁ 1 9 2 0 , ▁the ▁Cit ad elle ▁has ▁been ▁the ▁home ▁station ▁of ▁the ▁Royal ▁ 2 2 e ▁Rég iment ▁of ▁the ▁Canadian ▁Forces . ▁ ▁The ▁Quebec ▁Con ferences ▁of ▁ 1 9 4 3 ▁and ▁ 1 9 4 4 , ▁in ▁which ▁Governor ▁General ▁of ▁Canada ▁the ▁Earl ▁of ▁Ath l one , ▁Prime ▁Minister ▁of ▁Canada ▁William ▁Lyon ▁Mack en zie ▁King , ▁British ▁Prime ▁Minister ▁W inst on ▁Church ill , ▁and ▁US ▁President ▁Franklin ▁D . ▁Ro ose vel t ▁discussed ▁strategy ▁for ▁World ▁War ▁II , ▁were ▁held ▁at ▁the ▁Cit ad elle ▁of ▁Quebec . ▁ ▁The ▁Historic ▁S ites ▁and ▁Mon uments ▁Board ▁of ▁Canada ▁designated ▁the ▁Cit adel ▁as ▁a ▁national ▁historic ▁site ▁in ▁ 1 9 4 6 . ▁The ▁for tr ess ▁was ▁designated ▁as ▁a ▁National ▁Historic ▁Site ▁of ▁Canada ▁in ▁ 1 9 8 0 ▁and , ▁five ▁years ▁later , ▁the ▁Historic ▁District ▁of ▁Old ▁Québec , ▁of ▁which ▁the ▁Cit ad elle ▁is ▁a ▁part , ▁was ▁placed ▁on ▁UN ES CO ' s ▁list ▁of ▁World ▁Heritage ▁S