The economic downturn at the end of the 1920s and in the 30s created great social instability, and unemployment rose sharply. While the Social Democrats gained power in Denmark, the reaction to social instability was different in Germany, where Nazism gained a foothold. The result was the Second World War which broke out in 1939 and ended six years later with 60 million dead and Europe in ruins.

While Denmark was occupied by Germany Christian X served as a rallying point for the Danes, as he continued his daily rides on horseback through Copenhagen’s morning traffic. The King came to stand in contrast to the policy of collaboration and negotiation which he officially supported. Crown Prince Frederik (IX) and Crown Princess Ingrid likewise became popular, as did their first child Princess Margrethe (II), who was born a week after the German invasion. Christian X’s death in 1947 heralded new times for the Royal Family, which with Frederik IX gained a more approachable face.

Film, music, and art underwent rapid development during the period, and the importing of American culture took a firm hold in Europe. Modernism and functionalism revolutionised architecture and design.