Final answer:
The Edict of Restitution confiscated Protestant lands and restored them to Catholics, exacerbating tensions during the Thirty Years' War until it was modified by the Peace of Westphalia.
Step-by-step explanation:
The Edict of Restitution was a decree made during the Thirty Years' War in 1629 by Holy Roman Emperor Ferdinand II. Its primary action was to confiscate Protestant lands and restore them to the Catholic Church.
This edict attempted to reinforce the Peace of Augsburg from 1555, which allowed rulers in the empire to choose the religion (Catholicism or Lutheranism) of their territories.
However, the Edict of Restitution went further by also trying to restore Catholic proprietorships that had been secularized after 1552, which included many properties that had been in Protestant hands for decades.
The Edict of Restitution led to further tensions and continued conflict within the Holy Roman Empire, and it was ultimately modified significantly by the Peace of Westphalia, which ended the Thirty Years' War in 1648.