 John 's father @-@ in @-@ law , Leo I of Armenia , died several months before the crusaders seized Damietta . He bequeathed his kingdom to his infant daughter , Isabella . John and Raymond @-@ Roupen of Antioch ( Leo 's nephew ) questioned the will 's legality , each demanding the Armenian Kingdom of Cilicia for themselves . In a February 1220 letter , Pope Honorius declared John Leo 's rightful heir . <unk> that he wanted to assert his claim to Cilicia , John left Damietta for the Kingdom of Jerusalem around Easter 1220 . Although Al @-@ Mu 'azzam Isa 's successful campaign the previous year also pressed John to leave Egypt , Jacques de <unk> and other Fifth Crusade chroniclers wrote that he deserted the crusader army . 
