The Declaratio Ferdinandei ( ) was a clause in the Peace of Augsburg , signed Sign_agreement in 1555 to end Process_end conflicts Hostile_encounter between Catholics and Protestants within the Holy Roman Empire .

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 ) .

After Catholic victories Earnings_and_losses early in the Thirty Years ' War Hostile_encounter , the `` Declaratio Ferdinandei '' was overturned Process_end in the Edict Legal_rulings of Restitution of 1629 , which was part of Ferdinand II 's master plan Arranging to reconvert the Holy Roman Empire to Catholicism .

The overturning Process_end of the `` Declaratio Ferdinandei '' and other religious persecution Bodily_harm helped Assistance rekindle Recovering the Thirty Years ' War Hostile_encounter , changing Change it from an internal conflict Hostile_encounter within the Holy Roman Empire into an international religious war Hostile_encounter .

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 .

Also under the `` Declaratio Ferdinandei '' , Lutheran knights were given Giving the freedom Releasing to retain Defending their religion wherever they lived .

The revocation of the `` Declaratio Ferdinandei '' by the Catholics in the `` Edict of Restitution '' helped Assistance fuel the Thirty Years War .