The German-speaking states of the early modern period (c. 1500–1800) were divided politically and religiously. Religious tensions between the states comprising the Holy Roman Empire had existed during the preceding period of the Late Middle Ages (c. 1250–1500), notably erupting in Bohemia with the Hussite Wars (1419–1434). The defining religious movement of this period, the Reformation, led to unprecedented levels of violence and political upheaval for the region.
Usually considered to have begun with the publication of the Ninety-five Theses (1517) by Martin Luther in the city of Wittenberg (then within the Electorate of Saxony, now located within the modern German state of Saxony-Anhalt), the progression of the Reformation would divide the German states among new religious lines: the north, the east, and many of the major cities—Strasbourg, Frankfurt, and Nuremberg—becoming Protestant while the southern and western regions largely remained Catholic. Compromises and reforms would be made in an effort to promote internal stability within the Holy Roman Empire, importantly with the Peace of Augsburg in 1555, but these efforts would ultimately fall short and culminate in one of the most destructive conflicts the European continent had yet seen, the Thirty Years' War (1618–1648) which ended with the adoption of the incredibly consequential Peace of Westphalia.
This period also saw the emergence of the Kingdom of Prussia as the primary competitor to the previously hegemonic Habsburg monarchy. After the close of early modern period in Europe following the Age of Enlightenment and the dissolution of the Holy Roman Empire in 1806 during the Napoleonic Wars, this Austria-Prussia rivalry would prove to be the driving internal force behind the Unification of Germany in 1871.