The Duchies of Schleswig and Holstein are two historical regions located in northern Europe, primarily in what is now Germany and Denmark. They were once part of the Danish Kingdom and were significant in the political landscape of the 19th century, particularly during the conflicts between Denmark and the German states. In the mid-1800s, the duchies became a focal point of nationalist movements and territorial disputes. The Second Schleswig War in 1864 resulted in Prussia and Austria defeating Denmark, leading to the annexation of both duchies. Eventually, they became part of the German Empire in 1871, shaping the region's modern history.