Advanced Placement (AP) European History Practice Exam

The Peace of Westphalia, signed in 1648, is significant for its recognition of the sovereignty of over 300 German principalities, which played a crucial role in the development of modern nation-states. This peace treaty effectively ended the Thirty Years' War, a devastating conflict that involved many European powers and resulted in profound political and social changes.

One of the key principles established by the Peace of Westphalia was the idea of state sovereignty. By acknowledging the rights of individual principalities to govern themselves without outside interference, it laid the foundation for the modern international system of sovereign states. This treaty also emphasized the importance of diplomatic negotiation and balance of power, shaping how European countries would interact with one another in the future.

In contrast, other options do not accurately represent the outcomes of the Peace of Westphalia. The treaty did not unify all European countries under a single ruler or promote the rise of the Ottoman Empire in Europe. Additionally, the Byzantine Empire had already fallen earlier in the 15th century, so its return was not part of this treaty's effects. Thus, the recognition of the sovereignty of numerous German principalities is indeed the key outcome that aligns with the historical significance of the Peace of Westphalia.