when did denmark lose schleswig and holstein to prussia
History of Schleswig-Holstein In March 1848 these differences led to an open uprising by the German-minded Estate assemblies in the duchies in support of independence from Denmark and of close association with the German Confederation. The military intervention of Prussia helped the uprising: the Prussian army drove Denmark's troops from Schleswig and Holstein.
Unification of Germany Historians debate whether Otto von Bismarck—Minister President of Prussia—had a master plan to expand the North German Confederation of 1866 to include the remaining independent German states into a single entity or simply to expand the power of the Kingdom of Prussia. They conclude that factors in addition to the strength of Bismarck's Realpolitik led a collection of early modern polities to reorganize political, economic, military, and diplomatic relationships in the 19th century. Reaction to Danish and French nationalism provided foci for expressions of German unity. Military successes—especially those of Prussia—in three regional wars generated enthusiasm and pride that politicians could harness to promote unification. This experience echoed the memory of mutual accomplishment in the Napoleonic Wars, particularly in the War of Liberation of 1813–14. By establishing a Germany without Austria, the political and administrative unification in 1871 at least temporarily solved the problem of dualism.