Act of Union

Iceland [1918]

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July 14, 2026

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The Act of Union in 1918 established Iceland as a separate kingdom under the Danish crown, with Denmark retaining control over foreign affairs. This period, from 1904 to 1918, was marked by significant progress in Iceland, including advancements in fishing technology, education with the establishment of the University of Iceland, and expanded democratic rights, granting suffrage to women and propertyless men.12

The treaty allowed either party to review its terms, with a provision for termination after 25 years if negotiations for renewal failed. The German occupation of Denmark in 1940 effectively dissolved the union. By 1944, Iceland declared itself a republic, severing all constitutional ties with Denmark and achieving full independence. The Icelandic flag was also officially recognized in 1918 and later altered when Iceland became a republic.123

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Iceland
Home rule and sovereignty (1904–44)
On December 1, 1918, Iceland became a separate state under the Danish crown, with only foreign affairs remaining under Danish control. Either party, however, had the right to call for a review of the treaty, and if negotiations about its renewal proved fruitless at the end…
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On December 1, 1918, Iceland became a separate state under the Danish crown, with only foreign affairs remaining under Danish control. Either party, however, had the right to call for a review of the treaty, and if negotiations about its renewal proved fruitless at the end…
Read More