▁his ▁Norman ▁practice ▁by ▁which ▁he ▁had ▁become ▁a ▁rich ▁man . ▁The ▁most ▁important ▁of ▁his ▁works , ▁his ▁treat ise ▁De ▁recuper ation e ▁terra e ▁san ct ae , ▁was ▁written ▁in ▁ 1 3 0 6 , ▁and ▁dedicated ▁in ▁its ▁ext ant ▁form ▁to ▁Edward ▁I , ▁though ▁it ▁is ▁certainly ▁addressed ▁to ▁Philip . ▁ ▁Dub ois ▁out lines ▁the ▁conditions ▁necessary ▁to ▁a ▁successful ▁cr us ade — the ▁establishment ▁and ▁enfor cement ▁of ▁a ▁state ▁of ▁peace ▁among ▁the ▁Christian ▁nations ▁of ▁the ▁West ▁by ▁a ▁council ▁of ▁the ▁church ; ▁the ▁reform ▁of ▁the ▁mon astic , ▁and ▁especially ▁of ▁the ▁military , ▁orders ; ▁the ▁reduction ▁of ▁their ▁reven ues ; ▁the ▁instruction ▁of ▁a ▁number ▁of ▁young ▁men ▁and ▁women ▁in ▁orient al ▁languages ▁and ▁the ▁natural ▁sciences ▁with ▁a ▁view ▁to ▁the ▁government ▁of ▁Eastern ▁pe op les ; ▁and ▁the ▁establishment ▁of ▁Charles ▁of ▁Val ois ▁as ▁em peror ▁of ▁the ▁East . ▁The ▁king ▁of ▁France ▁was ▁in ▁fact , ▁when ▁once ▁the ▁po pe ▁was ▁dep riv ed ▁of ▁the ▁temporal ▁power , ▁to ▁become ▁the ▁su zer ain ▁of ▁the ▁Western ▁nations , ▁and ▁in ▁a ▁later ▁and ▁separate ▁mem oir ▁Dub ois ▁proposed ▁that ▁he ▁should ▁cause ▁himself ▁to ▁be ▁made ▁em peror ▁by ▁Pope ▁Clement ▁V . ▁ ▁His ▁ze al ▁for ▁the ▁cr us ade ▁was ▁probably ▁sub ordinate ▁to ▁the ▁desire ▁to ▁secure ▁the ▁wealth ▁of ▁the ▁mon astic ▁orders ▁for ▁the ▁royal