The Treaty of Vienna concluded a pivotal moment in Northern European relations following the Second War of Schleswig, which erupted due to rising tensions over the control of the duchies of Schleswig and Holstein. After a swift military campaign in 1864, Danish forces faced overwhelming defeat against the combined armies of Prussia and Austria. The treaty marked Denmark's formal cession of both provinces; Schleswig was granted to Prussia, and Holstein was awarded to Austria. The negotiations were necessary to stabilize tensions in the region, showcasing the dual interests of Prussia and Austria in expanding their influence over the German states.

The backdrop of this treaty can be traced to shifting national identities and the rise of nationalism, particularly in German-speaking territories. Denmark's attempts at integrating the duchies led to backlash from local populations who identified more closely with German nationalism. Consequently, the war and subsequent treaty reflected growing nationalist sentiments throughout Europe, especially in the context of the unification movements within Germany.

The implications of the treaty extended far into the political landscape of Europe. Denmark's loss signified not only a territorial punishment but also a shift that would eventually contribute to the rise of Prussia as a dominant power in Europe. The arrangement set the stage for future conflicts, such as the Austro-Prussian War of 1866, as the rivalry between Austria and Prussia intensified over the control of the southern German states. As such, the Treaty of Vienna was significant in reshaping the geopolitical map of Northern Europe and furthering the ambitions of the emerging nation-states.