itution , ▁passed ▁eleven ▁years ▁into ▁the ▁Th irty ▁Years ' ▁War ▁on ▁March ▁ 6 , ▁ 1 6 2 9 , ▁following ▁Catholic ▁success es ▁at ▁arms , ▁was ▁a ▁bel ated ▁attempt ▁by ▁Ferdinand ▁II , ▁Holy ▁Roman ▁Emperor ▁to ▁restore ▁the ▁religious ▁and ▁territorial ▁situations ▁reached ▁in ▁the ▁Peace ▁of ▁A ugs burg ▁( 1 5 5 5 ), ▁whose ▁" E cc les iast ical ▁Res ervation " ▁had ▁imp eded ▁the ▁sec ular ization ▁of ▁Catholic ▁church ▁lands ▁after ▁ 1 5 5 5 , ▁as ▁no ▁further ▁Catholic ▁church ▁lands ▁could ▁leg ally ▁be ▁transferred ▁to ▁Protest ant ▁control . ▁However , ▁for ▁several ▁dec ades ▁weak ▁em per ors ▁had ▁been ▁unable ▁to ▁en force ▁the ▁" E cc les iast ical ▁Res ervation " ▁against ▁Protest ant ▁enc ro ach ments . ▁ ▁Background ▁▁ ▁This ▁lack ▁of ▁decis ive ▁or ▁effective ▁authority ▁along ▁with ▁the ▁Protest ant ▁view ▁of ▁the ▁legal ▁interpretation ▁as ▁well ▁as ▁the ▁value ▁of ▁the ▁land ▁and ▁the ▁characteristic ▁dis like ▁for ▁all ▁things ▁Catholic ▁led ▁several ▁princes ▁to ▁sec ular ize ▁the ▁Catholic ▁church ▁lands ▁under ▁the ▁treat y ▁established ▁and ▁custom ary ▁practice ▁of ▁cui us ▁reg io , ▁e ius ▁relig io . ▁This ▁usually ▁occurred ▁when ▁a ▁Catholic ▁head ▁of ▁the ▁church ▁converted ▁to ▁Protest ant ism . ▁ ▁The ▁Peace ▁of ▁A ugs burg , ▁signed ▁in ▁ 1 5 5 5 , ▁had ▁confirmed ▁the ▁result ▁of ▁the ▁Diet ▁of ▁Spe yer ▁(