According to smber, the 1939 elections at the Folketing they secured 64 seats for the Social Democrats, 30 for the Liberals, 26 for the Conservatives, 14 for the Radicals, 3 for the Communists and 11 for other parties. The radical-socialist cabinet, chaired by Th. Stauning, therefore remained in office. As the offer of a non-aggression pact arrived from Berlin on April 29, 1939 after the occupation of Prague, Denmark, unique among the Nordic powers, accepted the German proposal and was the Danish foreign minister P. Munch to sign the pact on May 31 of the same year. In the spring of 1940, Nazi Germany occupied Norway and Denmark. On April 8, 1940, the first rumors about the imminent German action reached the Danish capital, but despite having been requested by the supreme commander of the Danish armed forces, gen. Prior, the mobilization, the Stauning cabinet refused to adopt this measure. Indeed, Foreign Minister Munch stated that Denmark would only commit arms if Danish neutrality was violated.

Having the governments of England and France communicated, on April 8, 1941, to the Norwegian one, that they had decided to inhibit, for the protection of their interests, the passage through Norwegian territorial waters of German ships trafficking between Germanic ports and the Norwegian one of Narvik, the German government announced, the following day, that “to prevent the violation by the British of Danish and Norwegian neutrality, the Germanic forces assumed the armed protection of the two countries”. In the very early hours of the morning of 9 April, German motorized and armored forces, under the command of gen. Kaupisch, crossed the border between Flensburg and Tondern, advancing decisively north, while others disembarked from ships escorted by cruisers, in ports of the Small and Great Belts. So quickly the German troops radiated through the Danish territory, the capital of which was occupied without any opposition, the Christian king having limited himself to issuing a proclamation to the nation, in which he declared that he was giving in to force. Subsequently, following the vote of the two Chambers, the king decided to place the neutrality of the country under German protection.

The Germans tried to get the cooperation of the Danes in the fight against England. They allowed the king, the government, the Riksdag and the various administrations continued their activities undisturbed; that there was no censorship on the radio and the press; in short, that life continued to unfold normally, without any foreign interference. Faced with the new situation, Th. Stauning felt the need to proceed with an enlargement of the cabinet with the addition of liberals and conservatives. In July 1940, Fr. Munch also left the direction of foreign policy and was replaced by H. Scavenius, a distinctly Germanophile. This was a consequence of the fall of France. The new coalition cabinet set out to “promote Danish national collaboration,” while simultaneously intending to preserve democratic institutions. There was therefore no objection to German requests to prove the formal accession of Denmark to the Axis powers. In July 1940 Denmark withdrew from the League of Nations; a year later (July 1941) the establishment of a Danish regiment of volunteers was allowed to fight against Russia. Furthermore, Denmark broke off diplomatic relations with the USSR, recognized the Man-chu kwo and Croatia, joined the antícomintern pact in November 1941. But this Danish attitude misled the Germans: they believed in fact that they could force Denmark to renounce. certainly to democratic institutions and to include it in their vital space, under the direct control of Berlin. The intentions of the Danes, on the other hand, were quite different, unable to openly oppose German requests, they found an outlet for their aversion in the underground resistance movement. invader. This resistance was explained in particular after the accession of Denmark to the anti-Comintern pact; but as early as April 1941, the Danish minister in Washington, HLH Kauffmann, had taken a clearly anti-German position, signing an agreement with the United States which temporarily granted the American troops the occupation of Greenland. Meanwhile, in London, the Danes against the German occupation had gathered and this assembly was joined, among others, by the head of the conservative party, Christmas Möller, who had joined the Stauning cabinet in 1940 and who in 1942 managed to flee to England. On the death of Stauning (May 1942), a cabinet presided over by the Minister of Finance V. Buhl took office who, being prepared, like his predecessor, to collaborate with Germany on an equal footing, however, did not intend to renounce at any cost the integrity and political independence of Denmark. Germany, considering this state of affairs, then decided to use the strong way. The commander-in-chief of the German troops in Denmark Lüdtke was replaced by gen. von Hanneken, who immediately introduced a series of measures intended to intimidate the Danish people. In addition, the Foreign Minister H. Scavenius, a grateful person in Berlin, in October 1942 had an interview with J. von Ribbentrop in the capital of the Reich, in which the German Foreign Minister communicated the he then decided to use the strong way. The commander-in-chief of the German troops in Denmark Lüdtke was replaced by gen. von Hanneken, who immediately introduced a series of measures intended to intimidate the Danish people. In addition, the Foreign Minister H. Scavenius, a grateful person in Berlin, in October 1942 had an interview with J. von Ribbentrop in the capital of the Reich, in which the German Foreign Minister communicated the he then decided to use the strong way. The commander-in-chief of the German troops in Denmark Lüdtke was replaced by gen. von Hanneken, who immediately introduced a series of measures intended to intimidate the Danish people. In addition, the Foreign Minister H. Scavenius, a grateful person in Berlin, in October 1942 had an interview with J. von Ribbentrop in the capital of the Reich, in which the German Foreign Minister communicated the ultimatum to form a new Danish government within four days, excluding all personalities disliked by Germany. The new government was then chaired by Scavenius himself, who also reserved the foreign portfolio. Elections at the Folketing were called in the spring of 1943which led to a sensational defeat of the Danish Nazis (they obtained only two per cent of the votes): the Social Democrats won 66 seats, 31 conservatives, 28 liberals, 13 radicals and 5 other parties.

Meanwhile, the resistance movement reported continued successes. Strikes were organized to sabotage supplies to the Germans, and acts of sabotage and attacks on the occupying troops, especially in Copenhagen, were carried out. In August 1943, Werner Best, the new German diplomatic representative in Copenhagen, asked the Danish government to proclaim a state of emergency. Faced with the admission made by Scavenius that he cannot count on the support of public opinion for the implementation of this serious measure, General von Hanneken proclaimed martial law and the capital was occupied by a strong contingent of German soldiers. The Danish army was disarmed, part of the fleet managed to escape to Sweden, part fell into the hands of the Germans. Street fighting occurred in Copenhagen due to the refusal of the Danish police to take an oath in the hands of the occupation authorities. The cabinet of Scavenius offered the resignation to the king, but they were rejected for fear that the Germans would take the opportunity to install an administration in the country under their direct control. The persecutions against the Jews began. Meanwhile the acts of sabotage and strikes continued. Faced with the Danish request to dissolve the unity of the SS. Danish “Schalburg” that he particularly distinguished himself in the persecution of fellow citizens, the Germans acquiesced in early July 1944, after the proclamation of the general strike; but then they proceeded to dissolve the Danish police, accused of agreeing with the saboteurs and strikers. Thus continued the struggle between the Danes and the invader, a struggle that ended on May 5, 1945, with the capitulation of the German troops. The new cabinet was formed by Buhl, head of the Social Democrats, and was made up of nine party representatives and nine leaders of the resistance movement. Having resolved the question of the island of Bornholm (which had been occupied by Russian troops, but later returned to Denmark), new elections were held in October 1945. The radical socialist majority in the Folketing, which had been maintained since 1929, when Stauning proceeded to form his second ministry, had ceased to exist and the votes it lost strengthened the positions of the liberals and communists. The Social Democrats in fact obtained only 48 mandates and the radicals 11, while 38 went to the liberals, 26 to the conservatives, 18 to the communists and 7 to other parties. A minority government was formed chaired by Knud Kristensen, leader of the liberals. The Kristensen cabinet remained in office until October 1947, when the Folketing he denied trust to the premier, due to his opinion in the question of southern Schleswig. Rejecting the radicals’ proposal to proceed with the formation of a coalition cabinet without calling new elections, Kristensen resigned the ministry to the king. On October 28, 1947, the electoral body gave its response, which assigned 57 seats to the Social Democrats, 46 to the Liberals, 17 to the Conservatives, 10 to the Radicals, 9 to the Communists and 6 to the Retsförbundet. In mid-November, a Social Democratic government supported by Laborites and chaired by Hans Hedtoft took office, with Gustav Rasmussen in charge of foreign affairs.

By joining the Marshall Plan, the Danish premier, in a speech in Vesterbro, on February 3, 1948, absolutely excluded any participation in a policy of blockades. On April 20, 1947, King Christian X died and was succeeded by Frederick IX.