During the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

(1914 - 1918),

Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Danish Realm, Kingdom of Denmark ...

maintained its neutrality. The position of neutrality was agreed to by all the major political parties. Denmark maintained trade with both sides of the war, and was among several neutral countries that exported

canned meat Potted meat is a form of traditional food preservation in which hot cooked meat is placed in a pot, tightly packed to exclude air, and then covered with hot fat. As the fat cools, it hardens and forms an airtight seal, preventing some spoilage by ...

to the German army. Danish speculators made fortunes on canned meat products, which were often of mediocre quality. 275 Danish

merchant ship A merchant ship, merchant vessel, trading vessel, or merchantman is a watercraft that transports cargo or carries passengers for hire. This is in contrast to pleasure craft, which are used for personal recreation, and naval ships, which are u ...

s were sunk, and approximately 700 Danish sailors perished during the war.

Fortification measures

At the outbreak of war, Denmark mobilized around 50,000 reservists to man

Copenhagen Copenhagen ( or .; da, København ) is the capital and most populous city of Denmark, with a proper population of around 815.000 in the last quarter of 2022; and some 1.370,000 in the urban area; and the wider Copenhagen metropolitan ar ...

's fortifications. This was about half the force that Denmark was expected to mobilize in case of war. By limiting its mobilization and calling the mobilized units "security forces" (''Sikringsstyrken''), the Danish government was trying to reassure the major powers that it was not intending to join the war. An additional '' Tunestillingen'' ("Tune Line") defense installation was constructed during the war. It stretched from

Køge Bay Køge Bay ( da, Køge Bugt) is an approximately shallow Danish bay in the southern part of Øresund, between Greater Copenhagen area in the North (or more precisely the southernmost peak of Amager) and Stevns Klint in the South, and as a part ...

and to

Roskilde Fjord Roskilde Fjord is the fjord north of Roskilde, Denmark. It is a long branch of the Isefjord. Cities The cities Frederiksværk, Frederikssund, Jægerspris, Jyllinge and Roskilde (including Himmelev), (home to the famous Roskilde Festival), all h ...

. The war brought to the fore the fact that Copenhagen's old fortifications from the 1880s and 1890s were obsolete and too near the capital to protect it from modern artillery bombardment.

Mining of Danish territorial waters

The Danish government bowed to pressure from

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

, and had

naval mine A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any ...

s laid in Danish waters with tacit

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

acceptance, despite the fact that Denmark was obliged under

international law International law (also known as public international law and the law of nations) is the set of rules, norms, and standards generally recognized as binding between states. It establishes normative guidelines and a common conceptual framework for ...

to keep its territorial waters open. The Germans had already begun to mine Danish territorial waters in order to protect Germany from a British naval offensive. By mining its own maritime area the Danish government was trying to avoid giving Germany a pretext for an occupation.

Ethnically Danish population of Southern Jutland

During the war, more than 30,000 ethnically Danish men from the

Southern Jutland Southern Jutland ( da, Sønderjylland; German: Südjütland) is the name for the region south of the Kongeå in Jutland, Denmark and north of the Eider (river) in Schleswig-Holstein, Germany. The region north of the Kongeå is called da, Nørr ...

region in the Prussian

Province of Schleswig-Holstein The Province of Schleswig-Holstein (german: Provinz Schleswig-Holstein ) was a province of the Kingdom of Prussia (subsequently the Free State of Prussia after 1918) from 1868 to 1946. History It was created from the Duchies of Schleswig and H ...

served in the German armed forces. In total, about 5,300 men from Southern Jutland fell during the war.

Post-War Territorial Changes

After the conclusion of the war, the

1920 Schleswig plebiscites The Schleswig plebiscites were two plebiscites, organized according to section XII, articles 100 to 115 of the Treaty of Versailles of 28 June 1919, in order to determine the future border between Denmark and Germany through the former Duchy of S ...

were held in German territory in compliance with the

Treaty of Versailles The Treaty of Versailles (french: Traité de Versailles; german: Versailler Vertrag, ) was the most important of the peace treaties of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June ...

Northern Schleswig South Jutland County (Danish: ''Sønderjyllands Amt'') is a former county (Danish: ''amt'') on the south-central portion of the Jutland Peninsula in southern Denmark. The county was formed on 1 April 1970, comprising the former counties of Aaben ...

was awarded to Denmark after 74.9% of the territory's population voted in favor of joining Denmark.

References

{{WWI history by nation, state=collapsed

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

World War I by country Denmark in World War I