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 Altranstädt (1707) Treaty of Altranstädt (1707) The Treaty or Convention of Altranstädt was signed between Charles XII of Sweden and Joseph I, Holy Roman Emperor on 31 August 1707. It settled the rights of Protestants in Silesia. While the Protestant Reformation had strongly affected Silesia, the Habsburg emperors had subjected the province to the counter-reformation in the 18th century. Especially in Upper Silesia, these measures were successful: in the early 18th century, almost half of the Silesian population was Roman Catholic and some 1,000 churches had been rededicated from Protestant to Roman Catholic. The Peace of Westphalia (1648) protected Protestants only in