The Thirty Years’ War lasted from 1618 to 1648, involving most of the countries of western Europe. At first it was primarily based on religious tensions between Roman Catholics and Protestants. Later, it was influenced by other issues, including the dynastic rivalries of German princes and the determination of certain powers, notably Sweden and France, to curb the power of the Holy Roman Empire. The Peace of Westphalia ended the war in 1648. It badly weakened the Holy Roman Empire, and established Switzerland and the Netherlands as independent states. Germany was ravaged by the war, and left politically divided and economically crippled.