The Schleswig-Holstein Question refers to a complex political and territorial dispute in the 19th century concerning the regions of Schleswig and Holstein, located in present-day northern Germany and southern Denmark. The question arose from the conflicting claims of Denmark, which sought to incorporate both duchies, and the German Confederation, which aimed to unite them with the German states. The dispute led to several conflicts, including the Second Schleswig War in 1864, where Prussia and Austria defeated Denmark. Ultimately, the territories were annexed by Prussia and Austria, and later, after the Austro-Prussian War in 1866, they became part of the newly formed German Empire.