5 0 % ▁of ▁the ▁Catholic ▁cler gy ▁were ▁active ▁supp or ters ▁of ▁the ▁U sta še ▁regime . ▁U sta še ▁cr imes ▁committed ▁against ▁the ▁Ser bian ▁population ▁were ▁generally ▁done ▁so ▁under ▁the ▁pre text ▁ ▁of ▁expand ing ▁Catholic ism ▁in ▁the ▁region . ▁For ▁example , ▁the ▁majority ▁of ▁Ser bi ans ▁intern ed ▁in ▁N D H ▁concentration ▁cam ps ▁were ▁intern ed ▁due ▁to ▁the ▁fact ▁that ▁they ▁refused ▁to ▁convert ▁to ▁Catholic ism . ▁In ▁many ▁municipal ities ▁around ▁the ▁N D H , ▁warning ▁post ers ▁declared ▁that ▁any ▁Ser b ▁who ▁did ▁not ▁convert ▁to ▁Catholic ism ▁would ▁be ▁deport ed ▁to ▁a ▁concentration ▁camp . ▁ ▁Catholic ▁hierarchy ▁ ▁Arch bishop ▁Ste pin ac ▁ ▁Arch bishop ▁Alo ys ius ▁Ste pin ac ▁of ▁Zag reb ▁was , ▁at ▁the ▁time ▁of ▁his ▁appointment ▁in ▁ 1 9 3 4 ▁at ▁the ▁age ▁of ▁ 3 9 , ▁the ▁young est ▁Catholic ▁bishop ▁in ▁the ▁world . ▁He ▁initially ▁received ▁very ▁little ▁guidance ▁from ▁the ▁V at ican ▁and ▁was ▁given ▁great ▁le ew ay ▁in ▁how ▁to ▁deal ▁with ▁the ▁rise ▁of ▁the ▁U sta še . ▁His ▁control ▁over ▁the ▁lower ▁b ish ops ▁and ▁cler gy ▁was ▁not ▁uniform . ▁Histor ian ▁of ▁the ▁Hol oca ust ▁Martin ▁Gilbert ▁wrote ▁that , ▁" Ste pin ac , ▁who ▁in ▁ 1 9 4 1 ▁had ▁wel com ed ▁Cro at ▁independence , ▁subsequently ▁condem ned ▁Cro at ▁at