European Union law fair dealing through their business. In 1517, the Protestant Reformation triggered a hundred years of crisis and instability. Martin Luther nailed a list of demands to the church door of Wittenberg, King Henry VIII declared a unilateral split from Rome with the Act of Supremacy 1534, and conflicts flared across the Holy Roman Empire until the Peace of Augsburg 1555 guaranteed each principality the right to its chosen religion ("cuius regio, eius religio"). This unstable settlement unravelled in the Thirty Years' War (1618–1648), killing around a quarter of the population in central Europe. The Treaty of Westphalia 1648, which brought
Treaty of the Pyrenees Spanish Habsburg victories in the Dutch Revolt in the 1620s and at the Battle of Nördlingen against Sweden in 1634. By 1640, France began to interfere in Spanish politics, aiding the revolt in Catalonia, while Spain responded by aiding the Fronde revolt in France in 1648. During the negotiations for the Peace of Westphalia in 1648, France gained the Sundgau and cut off Spanish access to the Netherlands from Austria, leading to open warfare between the French and Spanish. After 23 years of war, an Anglo-French alliance was victorious at the Battle of the Dunes in June 14, 1658, but