The First War of Villmergen was a Swiss religious war which lasted from 5 January until 7 March 1656, at the time of the Old Swiss Confederacy. On the one hand were the Protestant cities of Zürich and Bern, on the other the Catholic places in Central Switzerland. The Protestants tried to break the political hegemony of the Catholics, that had been in existence ever since the Second Kappel Landfrieden of 1531. The casus belli was the expulsion and execution of Protestants from the Schwyz commune of Arth. The Zürcher unsuccessfully besieged the Central Swiss-allied city of Rapperswil and thereby drove their forces together. The Bernese were defeated and repelled in the First Battle of Villmergen. The Third Landfrieden ended the conflict and restored the pre-war balance of power.