The Thirty Years' War (1618–1648), devastating large parts of the Holy Roman Empire, fell into this period. Although the war was mostly a conflict between Protestants and Catholics, Catholic France sided with the Protestants against the Austrian-led Catholic Imperial forces. The Peace of Westphalia in 1648 gave France part of Alsace. The 1679 Treaties of Nijmegen consolidated this result by bringing several towns under French control. In 1681, Louis XIV marched into the city of Strasbourg on September 30, and proclaimed its annexation.