German Catholic League

The Catholic League (Latin: Liga Catholica, German: Katholische Liga) was a coalition of Catholic states of the Holy Roman Empire formed 10 July 1609. While initially formed as a confederation to act politically to negotiate issues vis-à-vis the Protestant Union (formed 1608), modelled on the more intransigent ultra-Catholic French Catholic League (1576), it was subsequently concluded as a military alliance "for the defence of the Catholic religion and peace within the Empire".

Notwithstanding the league's founding, as had the founding of the Protestant Union, it further exacerbated long standing tensions between the Protestant reformers and the adherents of the Catholic Church which thereafter began to get worse with ever more frequent episodes of civil disobedience, repression, and retaliation that would eventually ignite into the first phase of the Thirty Years' War roughly a decade later with the act of rebellion and calculated insult known as the Second Defenestration of Prague on 23 May 1618.

In 1555, the Peace of Augsburg was signed, which confirmed the result of the Diet of Speyer (1526) and ended the violence between the Catholics and the Lutherans in the Holy Roman Empire.

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