ade ▁ 1 2 2 8 – 1 2 2 9 ▁ ▁Emperor ▁Frederick ▁II ▁had ▁repeatedly ▁v owed ▁a ▁cr us ade ▁but ▁failed ▁to ▁live ▁up ▁to ▁his ▁words , ▁for ▁which ▁he ▁was ▁ex communic ated ▁by ▁Pope ▁Gregory ▁IX ▁in ▁ 1 2 2 8 . ▁He ▁non eth eless ▁set ▁sail ▁from ▁Br ind isi , ▁land ed ▁in ▁Palest ine , ▁and ▁through ▁diplom acy ▁he ▁achieved ▁unexpected ▁success : ▁Jerusalem , ▁Naz are th , ▁and ▁Beth le hem ▁were ▁delivered ▁to ▁the ▁cr us aders ▁for ▁a ▁period ▁of ▁ten ▁years . ▁ ▁In ▁ 1 2 2 9 ▁after ▁failing ▁to ▁conquer ▁Egypt , ▁Frederick ▁II ▁of ▁the ▁Holy ▁Roman ▁Empire ▁made ▁a ▁peace ▁treat y ▁with ▁Al - K amil . ▁This ▁treat y ▁allowed ▁Christians ▁to ▁rule ▁over ▁most ▁of ▁Jerusalem , ▁while ▁the ▁Muslim s ▁were ▁given ▁control ▁of ▁the ▁D ome ▁of ▁the ▁Rock ▁and ▁the ▁Al - A ks a ▁mos que . ▁The ▁peace ▁brought ▁about ▁by ▁this ▁treat y ▁last ed ▁for ▁about ▁ten ▁years . ▁Many ▁of ▁the ▁Muslim s ▁though ▁were ▁not ▁happy ▁with ▁Al - K amil ▁for ▁giving ▁up ▁control ▁of ▁Jerusalem , ▁and ▁in ▁ 1 2 4 4 , ▁following ▁a ▁sie ge , ▁the ▁Muslim s ▁reg ained ▁control ▁of ▁the ▁city . ▁ ▁Se vent h ▁Cr us ade , ▁ 1 2 4 8 – 1 2 5 4 ▁ ▁The ▁pap al ▁interests ▁represented ▁by ▁the ▁Kn