The primary cause of the Peace of Augsburg in 1555 was the long-standing religious conflict between Catholics and Lutherans within the Holy Roman Empire. The wars of religion, particularly the Schmalkaldic War, intensified the strife, prompting the need for a settlement. The Peace of Augsburg allowed each prince within the empire to determine the official religion—either Catholicism or Lutheranism—of their own territory, establishing a framework for religious coexistence. This agreement was significant in reducing hostilities for a time, although it did not resolve deeper divisions in Europe, which persisted and eventually contributed to further conflicts in later decades.