MAP 18.1 Religious Divisions, ca. 1555 In the mid-sixteenth century, much of Europe remained Catholic. The Peace of Augsburg (1555) allowed the ruler of each territory in the Holy Roman Empire to determine the religion of its people. The northern territories of the empire became Lutheran, as did Scandinavia, while much of the southern empire remained Catholic. Sizable Calvinist populations existed in Scotland, the Netherlands, and central Europe. Eastern Europe was dominated by Orthodox Christianity, and the Ottoman Empire to the south and southeast was Muslim.