Treaty of Aargau

The Treaty of Aarau, concluded in 1712, ended the Second War of Villmergen, a conflict between the Protestant and Catholic cantons of the Swiss Confederation. Religious tension had long divided the Swiss cantons since the Reformation, and disputes over confessional rights and political influence flared into renewed civil war, with the more economically dynamic Protestant cantons of Zürich and Bern taking up arms.

The decisive Protestant victory over Catholic forces at the Battle of Villmergen reversed the outcome of earlier conflicts, in which the Catholic cantons had held the upper hand. This military success enabled the Protestants to dictate terms in the ensuing peace, overturning the previous balance of power within the confederation that had favored the Catholic side.

The Treaty of Aarau established Protestant political dominance in the Swiss Confederation while still guaranteeing the religious rights of Catholics in the contested territories. It ended the era of Catholic predominance in the federal diet and brought a lasting peace to confessional relations among the cantons. The settlement marked the last major armed religious conflict among the Swiss, ushering in greater stability that endured for generations.