The Protestant Reformation in Switzerland was promoted initially by Huldrych Zwingli, who gained the support of the magistrate, Mark Reust, and the population of Zürich in the 1520s. It led to significant changes in civil life and state matters in Zürich and spread to several other cantons of the Old Swiss Confederacy. Seven cantons remained Catholic, however, which led to intercantonal wars known as the Wars of Kappel. After the victory of the Catholic cantons in 1531, they proceeded to institute Counter-Reformation policies in some regions. The schism and distrust between the Catholic and the Protestant cantons defined their interior politics and paralysed any common foreign policy until well into the 18th century. Despite their religious differences and an exclusively-Catholic defence alliance of the seven cantons (Goldener Bund), no other major armed conflicts directly between the cantons occurred. Soldiers from both sides fought in the French Wars of Religion. During the Thirty Years' War, the thirteen cantons managed to maintain their neutrality, partly because all major powers in Europe depended on Swiss mercenaries and would not let Switzerland fall into the hands of one of their rivals. The Three Leagues (Drei Bünde) of the Grisons were not yet a member of the Confederacy but were involved in the war from 1620 onward, which led to their loss of the Valtellina from 1623 to 1639. Development of Protestantism After the violent conflicts of the late 15th century, the Swiss cantons had had a generation of relative political stability. As part of their struggle for independence, they had already in the 15th century sought to limit the influence of the Church on their political sovereignty. Many monasteries had already come under secular supervision, and the administration of schools was in the hands of the cantons, although the teachers generally still were priests. Nevertheless, many of the problems of the Church also existed in the Swiss Confederacy. Many a cleric, as well as the Church as a whole, enjoyed a luxurious lifestyle in stark contrast to the conditions of the large majority of the population; this luxury was financed by high church taxes and abundant sale of indulgences. Many priests were poorly educated, and spiritual Church doctrines were often disregarded. Many priests did not live in celibacy but in concubinage. The new reformatory ideas thus fell on fertile ground. The main proponent of the Reformation in Switzerland was Huldrych Zwingli, whose actions during