The Swiss Confederation, despite a series on inter-cantonal religious wars (the Kappel Wars of (1529–31) had survived the religious conflicts of the Reformation, and this relative peace was maintained during the Thirty Years’ War (1618–48). All the major competing powers relied on the professional services of the Swiss mercenaries, and would not therefore allow the Swiss territories to fall into the hands of rivals. Neutrality was emerging as an official policy of the Swiss Confederation, protecting against a weak foreign policy and avoiding internal strife. The Drei Bünde (Three Leagues) of the Graubünden (Grisons) were allied with the Confederation, but not a part of it, from the late 15th century. During the Thirty Years’ War the Grisons became a battleground between Protestants, supported by France and Venice, and Catholics, supported by Habsburgs in Spain and Austria – at the root of the conflict was control of the important transalpine passes. When a pro-Catholic rebel army emerged from Valtellina in 1620, resulting in a massacre of Protestants, Valtellina was ousted from the Leagues. A poorly led and disorganized Protestant army responded in 1621, but the attack collapsed and Spain and Austria had an excuse to invade and occupy the Graubünden. A series of conflicts ensued to expel the invaders and to bring Valtellina back into the Leagues. At the Treaty of Westphalia (1648), which concluded the war, Switzerland was granted legal independence from the Holy Roman Empire and Valtellina was confirmed as a dependency of the Drei Bünde.
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