The United Kingdom invades Iceland.
The invasion of Iceland by the Royal Navy and Royal Marines occurred on 10 May 1940, during World War II. The invasion was performed because the British government feared that the island would be used by the Germans, who had recently overrun Denmark, Iceland’s possessing country. The Government of Iceland issued a protest, charging that its neutrality had been “flagrantly violated” and “its independence infringed”.
At the start of the war, the UK imposed strict export controls on Icelandic goods, preventing profitable shipments to Germany, as part of its naval blockade. The UK offered assistance to Iceland, seeking co-operation “as a belligerent and an ally”, but Reykjavík refused and reaffirmed its neutrality. The German diplomatic presence in Iceland, along with the island’s strategic importance, alarmed the UK government.
After failing to persuade the Icelandic government to join the Allies, the UK invaded on the morning of 10 May 1940. The initial force of 746 Royal Marines commanded by Colonel Robert Sturges disembarked at the capital Reykjavík. Meeting no resistance, the troops moved quickly to disable communication networks, secure strategic locations, and arrest German citizens. Requisitioning local transport, the troops moved to Hvalfjörður, Kaldaðarnes, Sandskeið, and Akranes to secure potential landing areas against the possibility of a German counterattack.
During 1918, after a long period of Danish rule, Iceland had become an independent state in personal union with the Danish king and with common foreign affairs. The newly initiated Kingdom of Iceland declared itself a neutral country without a defence force. The treaty of union allowed for a revision to begin during 1941 and for unilateral termination three years after that, if no agreement was made. By 1928, all Icelandic political parties were in agreement that the union treaty would be terminated as soon as possible.
On 9 April 1940, German forces began Operation Weserübung, invading both Norway and Denmark. Denmark was subdued within a day and occupied. On the same day, the British government sent a message to the Icelandic government, stating that the UK was willing to assist Iceland in maintaining its independence but would require facilities in Iceland to do so. Iceland was invited to join the UK in the war “as a belligerent and an ally.” The Icelandic government rejected the offer. On the next day, 10 April, the Icelandic parliament, the Alþingi, declared Danish King Christian X unable to perform his constitutional duties and assigned them to the government of Iceland, along with all other responsibilities previously performed by Denmark on behalf of Iceland.
On 12 April, as Operation Valentine, the British occupied the Faroe Islands. After the German invasion of Denmark and Norway, the British government became increasingly concerned that Germany would soon try to establish a military presence in Iceland. They felt that this would constitute an intolerable threat to British control of the North Atlantic. Just as importantly, the British were eager to obtain bases in Iceland for themselves to strengthen their Northern Patrol.