| 1914 | August laws – increased state regulation of the economy |
| 1915 | New democratic constitution giving women and servants of both sexes the right to vote in parliamentary elections |
| 1917 | Sale of Danish West Indies to the USA (US Virgin Islands) |
| 1918 | Iceland recognised as an independent state in personal union with Danish crown |
| 1919 | Smallholders’ act guaranteed cheap government loans for new smallholdings |
| 1920 | Reunification of northern Schleswig after a referendum, establishing the current Danish–German border |
| 1920 | Easter Crisis following dissolution of the government by the king |
| 1922 | Collapse of Landmandsbanken |
| 1924 | First Social Democratic government, led by Prime Minister Stauning |
| 1926 | Liberal government led by Prime Minister Madsen-Mygdal |
| 1929-1940 | Social Democratic–Social Liberal coalition governments led by Prime Minister Stauning |
| 1931 | First crisis agreement between the government and the Conservative People’s Party |
| 1932 | Exchange Control Office (Valutacentralen) founded |
| 1933 | Kanslergade Agreement |
| 1935 | Peak support for Social Democratic Party, with 46% of the vote |
| 1935 | Opening of the first bridge across the Little Belt |
| 1938 | Holiday Act gave workers two weeks of statutory holiday a year |
| 1939 | Social Democratic government’s proposal for a new constitution rejected in referendum |
| 1939 | Non-aggression pact between Germany and Denmark |
| 1940 | German occupation of Denmark |
| 1941 | Denmark joined the German Anti-Comintern Pact |
| 1941 | Danish ambassador to Washington formalised a treaty with the US government putting Greenland under the control of the American military |
| 1942 | Emergence of resistance groups carrying out acts of sabotage against the German occupying power |
| 1943 | Major strikes directed against the occupying power; collapse of policy of co-operation |
| 1943 | Deportation of Danish Jews to German concentration camps; approximately 7,000 rescued |
| 1944 | Danish police force dissolved |
| 1944 | ‘People’s strike’ (folkestrejke) in Copenhagen |