Much has been written about the religious legitimization of political authority since the days of Marc Bloch and Ernst Kantorowicz. And yet the history of decision-making has not been included in this development. How can we study the influence of religious ideas on politics? This book analyzes how the Catholic Reformation tried to influence the political landscape in the first half of the 17th century. It looks at the resistance proffered against the anti-Spanish war policy in France, the Bavarian strategy during the 30-Year War and the collapse of the Polish monarchy in the 17th century. Damien Tricoire provides a multitude of new approaches to the role of politics and religion in the Premodern Period.