Global InformationFirst Schleswig War information
 | This article includes a list of general references, but it lacks sufficient corresponding inline citations. (February 2017) |
 | The examples and perspective in this article deal primarily with Germany and do not represent a worldwide view of the subject. (February 2022) |
| First Schleswig War | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Part of the revolutions of 1848 | |||||||||
 Danish soldiers return to Copenhagen in 1849 by Otto Bache (1894) | |||||||||
| |||||||||
| Belligerents | |||||||||
|
|
Supported by:  Russian Empire United Kingdom Sweden-Norway France | ||||||||
| Commanders and leaders | |||||||||
 Frederick of Noer Friedrich von Wrangel Felix Salm-Salm Karl Wilhelm von Willisen |
 Frederick VII of Denmark | ||||||||
| Casualties and losses | |||||||||
| 8,309 killed, wounded or captured | 8,695 killed, wounded or captured | ||||||||
The First Schleswig War (German: Schleswig-Holsteinischer Krieg), also known as the Schleswig-Holstein Uprising (German: Schleswig-Holsteinische Erhebung) and the Three Years' War (Danish: Treårskrigen), was a military conflict in southern Denmark and northern Germany rooted in the Schleswig-Holstein Question: who should control the Duchies of Schleswig, Holstein and Lauenburg, which at the time were ruled by the king of Denmark in a personal union. Ultimately, the Danish side proved victorious with the diplomatic support of the great powers, especially Britain and Russia, since the duchies were close to an important Baltic seaway connecting both powers.
The population was majority Danish in Northern Schleswig (roughly the area returned to Denmark after World War I), while in the rest of Schleswig and in Holstein and Lauenburg it was majority German.
In March 1848, the German population of Schleswig, Holstein, and Lauenburg rebelled, and created a provisional government and army. As Holstein and Lauenburg were member states, the German Confederation supported the rebels as a federal war (Bundeskrieg) according to its statutes. This was continued by the German Central Government (of the federal state that replaced the Confederation in 1848/49-51), with most of the German troops being provided by Prussia.
The war was interrupted in August 1848 by the armistice of Malmö, but started again with a Danish offensive in February 1849. In summer 1850, Prussia had to back down and leave the rebels to their fate. On 1 April 1851, the Schleswig-Holstein army was disbanded. The London Protocol of 1852 was the final settlement of the conflict with the great powers confirming the Danish king to be the duke of the duchies but also declaring that the duchies had to remain independent from Denmark proper.