The `` Declaratio Ferdinandei '' exempted knights and some of the cities under the jurisdiction Control of an ecclesiastical prince if they had practiced Practice Lutheranism for some time ( Lutheranism was the only branch of Protestantism recognized Know under the Peace ) .

The Cologne War Hostile_encounter ( 1583–88 ) was a conflict Hostile_encounter between Protestant and Catholic factions that devastated Destroying the Electorate of Cologne , a historical ecclesiastical principality of the Holy Roman Empire , within present-day North Rhine-Westphalia , in Germany .

Also called Name_conferral the Seneschal 's War or the Seneschal Upheaval and occasionally the Sewer War , the conflict tested Testing the principle of ecclesiastical reservation , which had been included Cause_to_be_included in the religious Peace of Augsburg ( 1555 ) .

This principle excluded Preventing_or_letting , or `` reserved Preserving '' , the ecclesiastical territories of the Holy Roman Empire from the application of `` cuius regio , eius religio '' , or `` whose rule , his religion '' , as the primary means of determining Deciding the religion of a territory .

It stipulated Statement instead that if an ecclesiastical prince converted Change to Protestantism , he would resign Change_of_leadership from his position rather than force Request the conversion of his subjects .

The principle of ecclesiastical reservation required Imposing_obligation his resignation .

Instead , he declared Expressing_publicly religious parity for his subjects and , in 1583 , married Forming_relationships Agnes von Mansfeld-Eisleben , intending to convert Change the ecclesiastical principality into a secular , dynastic duchy .

Now legal in the `` de jure '' sense , it was to apply Giving to all the territories of the Empire except for the Ecclesiastical principalities , and some of the cities in those ecclesiastical states , where the question of religion was addressed Statement under the separate Forming_relationships principles of the `` reservatum ecclesiasticum '' and the `` Declaratio Ferdinandei '' , which were also part of the Peace of Augsburg .

There were also clauses in relation to ecclesiastical lords .

When prelates who ruled Legal_rulings an ecclesiastical fiefdom converted Change , the expectation was placed Placing upon them to resign Process_end their temporal privileges .

The ' ( ecclesiastical reservation ) was a measure inserted into the Peace of Augsburg of 1555 to balance Cause_change_of_strength the principal proviso of ' in ecclesiastical lands .

The ' ( ecclesiastical reservation ) was a measure inserted into the Peace of Augsburg of 1555 to balance Cause_change_of_strength the principal proviso of ' in ecclesiastical lands .

If this same principle were applied Using in ecclesiastical lands , such as those ruled Legal_rulings by a prince-bishop or an abbot , the conversion of an incumbent to Lutheranism would convert Change the entire principality to Protestantism .