© Getty Images

April 9, 1940 -

At 4 am on April 9, 1940, Nazi Germany invaded neutral Denmark in a well-coordinated and organized attack.

© Getty Images 

Operation Weserübung -

Operation Weserübung was the code name for Germany's assault on Denmark and Norway.

© Getty Images

First clashes -

The first clash between the Danish Army and the invading forces occurred at Lundtoftbjerg, Jutland, when a German column met a Danish anti-tank platoon. Overwhelmed, the defenders soon had to withdraw to Åbenrå (pictured).

© Public Domain 

Bjergskov -

German forces met resistance at Bjergskov after Danish troops set up a roadblock in an attempt to halt the advance. But the Danes were outnumbered and quickly subdued. Pictured: disarmed Danish prisoners of war.

© Public Domain

Luftwaffe attack -

Meanwhile, the German Luftwaffe wiped out most of the Danish Army Air Service in one action. Pictured is the airfield at Værløse after an attack.

© Public Domain 

Bredevad -

Another encounter between Danish and German forces occurred at Bredevad. The Danes managed to disable four enemy armored cars before sustaining casualties and surrendering. Pictured is group of Danish soldiers on the morning of the German invasion.

© Public Domain 

Ready to fight back -

Danish soldiers, ready and willing but hopelessly outnumbered and inexperienced, man an anti-aircraft gun in April 1940.

© Getty Images 

Haderslev -

The town of Haderslev was a key target for the Germans, where a garrison of 225 men of the Jutland Division was stationed. In all, around 400 Danes defended the town before being ordered to surrender.

© Getty Images

Airborne and naval landings -

German paratroopers (the Fallschirmjäger) secured Storstrøm Bridge and the fortress on Masnedø island. Elsewhere, troops landed in Korsør (pictured) and Nyborg.

© Getty Images 

Korsør -

German radio operators wiring progress reports to Berlin after disembarking at Korsør.

© Getty Images 

Capture of Copenhagen -

A battalion of the 198th German Infantry disembarked from the minelayer Hansestadt Danzig and entered Copenhagen shortly after 05h00.

© Getty Images 

Propaganda raid -

While King Christian X and his ministers conferred with the Danish high command about the next course of action, German bombers drop OPROP! leaflets over Copenhagen.

© Public Domain 

OPROP! -

OPROP! was a German propaganda leaflet justifying the invasion and warning the population not to resist.

© Public Domain 

Denmark -

Faced with the threat of the Luftwaffe bombing Copenhagen's civilian population, the Danish government, headed by Prime Minister Thorvald Stauning (1873–1942), capitulated at 08:34 on April 9, 1940.

© Getty Images

The occupation begins -

A German infantry detachment being passed by a bus on the afternoon of April 9 as it marches towards the Danish capital. The attack on Denmark was a breach of the non-aggression pact the country had signed with Germany less than a year earlier.

© Getty Images 

Terms of occupation -

The invasion of Denmark lasted less than six hours and was the shortest military campaign conducted by Nazi Germany during the war. The Germans quickly set out their terms of occupation to the civilian population, using loudspeakers mounted on trucks (pictured).

© Getty Images

Protectorate Government 1940–43 -

Denmark had little choice other than to cooperate with the Germans. The government remained more or less intact, and parliament continued to function more or less as it had before. Pictured is Foreign Minister Erik Scavenius (left), later prime minister, with the Plenipotentiary of the German Reich in Denmark, Werner Best.

© Public Domain 

Werner Best (1903–1989) -

An ardent Nazi, SS general Werner Best was the civilian administrator of occupied Denmark from 1942 to 1945. Convicted of war crimes in Denmark in 1948, Best escaped the death penalty and was jailed for 12 years. He was released in 1951 as part of a Danish amnesty program for Nazi war criminals. He died in 1989.

© Public Domain 

National Socialist Workers' Party of Denmark -

The National Socialist Workers' Party of Denmark (DNSAP) supported Hitler's invasion and subsequent occupation of Denmark. Pictured: Frits Clausen, leader of the DNSAP from 1933–1945.

© Public Domain

Collaboration -

The DNSAP formed the Free Corps Denmark, a Danish volunteer force created in cooperation with Nazi Germany to fight the Soviet Union. Its formation was sanctioned by the Danish government, which authorized officers of the Danish Army to join its ranks.

© Public Domain

Collaborators -

The Copenhagen headquarters of the Schalburg Corps, a Danish Germanic SS unit. It was formed on February 2, 1943.

© Public Domain 

Life under occupation -

A soccer match in Hillerød between a German military team and one made up of Danish civilians.

© Getty Images 

Life under occupation -

A radio choir from Hamburg, in full voice for German occupation forces, sing in front of the city hall in Esbjerg.

© Getty Images 

Life under occupation -

Young Danish women fraternize openly with German troops.

© Getty Images 

The Telegram Crisis -

In September 1942, Hitler sent King Christian X a telegram congratulating the monarch on his birthday. The king's formal reply? "Giving my best thanks, King Christian." The Fuhrer, enraged by this deliberate slight, immediately recalled his ambassador and promoted the hardliner Werner Best as plenipotentiary. The crisis marked the beginning of increasing hostility towards Nazi rule.

© Public Domain

The mass escape of Jews -

On August 29, 1943, the Germans officially dissolved the Danish government and instituted martial law. The country was now exposed to the full extent of occupational rule. In October, the Germans decided to remove all Jews from Denmark. Pictured: a Polish passport used in Denmark up to March 1940. The Jewish holder escaped to Sweden in 1943.

© Public Domain 

Fleeing to Sweden -

The Gestapo had planned to raid Jewish homes on October 1 and deport all Danish Jews to concentration camps. However, when soldiers broke down doors across the country, they rounded up less than 300 people. Pictured: Danish Jews en route to Sweden.

© Getty Images

Safety and sanctuary -

A few days earlier, German diplomat Georg Duckwitz tipped off the Danes who in turn warned the Jewish population and urged them to leave. In all, 7,220 of Denmark's 7,800 Jews were evacuated over a two-month period, setting sail for neighboring Sweden from Danish beaches and ports with the assistance of many Danish citizens.

© Getty Images

Resistance intensifies -

By 1944, Danish resistance to German rule had intensified. Acts of sabotage against infrastructure were frequent, and an underground government was established.

© Public Domain 

Retribution -

By May of the following year, with Germany on the brink of defeat, resistance fighters were on the streets and seeking retribution.

© Getty Images

Humiliation -

Nazi collaborators—men and women—were arrested and marched through city streets.

© Getty Images

Liberation -

Most of Denmark was liberated from German rule in May 1945, by British forces commanded by Field Marshal Bernard Montgomery.

© Getty Images

German departure -

Men of the Danish resistance patrol the streets as motorized units of the German Army leave Denmark upon the surrender of Germany in May 1945. A crowd of delighted citizens watch the departure.

© Getty Images

End of the war -

Thousands of Danes line the streets as Field Marshal Bernard Montgomery drives through Copenhagen in May 1945.

© Public Domain 

Ryvangen Memorial Park -

Ryvangen Memorial Park in Copenhagen commemorates fallen members of the Danish resistance to the German occupation of Denmark. Approximately 39 Danish soldiers were killed or injured during the initial April 9, 1940 invasion. Roughly 3,000 Danish civilians were killed as a direct result of the occupation, and some 360 civilians died in concentration camps.

See also: Remembering the the Oradour-sur-Glane massacre

© Getty Images