the Arctic 1940: Invasion of Iceland

When the Danish government capitulated, Iceland assumed full control over its own affairs. Despite this, and Icelandic insistence on neutrality, the British still feared the possibility of Germany extending its influence over the island and invaded in May. The local authorities offered no resistance, reluctantly agreeing to cooperate with the Allies for the rest of the War.

Main Events

12–13 Apr 1940 Occupation of the Faroe Islands

Two British destroyers and the cruiser HMS Suffolk escorted 250 Royal Marines to Torshavn, Faroe Islands, pressuring the Danish Prefect to accept British occupation. The British would remain until the end of the war. in wikipedia

13 Apr–8 Jun 1940 Battles of Narvik

Following the German capture of Narvik, northern Norway, on 9 April 1940, the British Royal Navy returned in force to the port, defeating the German Kriegsmarine on 13 April and landing troops in nearby Harstad the following day. The British offensive was joined on land by the Norwegians, French, and Poles, but, despite local German setbacks, the Allies were eventually forced to evacuate after the German victories in France. in wikipedia

5 May 1940 Self-rule in Greenland

In light of the German occupation of Denmark, the Greenland local parliament voted to assume the powers the Danish government could no longer exercise, effectively becoming independent. The move was made in order to request United States protection. in wikipedia

10 May 1940 Invasion of Iceland

After the United Kingdom failed to persuade Iceland to join the Allies, 746 British Royal Marines under Colonel Robert Sturges disembarked at Reykjavik, the Icelandic capital, on the morning of 10 May 1940. Meeting no resistance other than curious crowds, the British occupied the rest of the island over the following weeks. Icelandic authorities adopted a policy of de facto cooperation with the invaders but maintained formal neutrality. in wikipedia

10–23 May 1940 Blitzkrieg in the West

In operation Fall Gelb (Case Yellow), German forces launched a simultaneous invasion of Belgium, Luxembourg, and the Netherlands. When the Allies in France raced north to protect the Low Countries, the Germans pushed armored units through the heavily forested Ardennes of southern Belgium into France in a surprise move to split the Allied forces. The German attack succeeded perfectly, overrunning northern France and isolating the British at Dunkirk. in wikipedia