After A. Hitler took office as German Chancellor (January 30, 1933) and the establishment of the National Socialist dictatorship in Germany (since February 1933; Reichstag fire, February 27), political life in the Reich capital was also brought into line, the various forms of cultural life were suppressed. The mayor now exercised purely administrative functions; J. Goebbels tried the political face of the city primarily to be appointed as Gauleiter of the NSDAP in Berlin (in 1940 he took over the duties of city president). The organization of the Olympic Games in Berlin in 1936 (construction of the “Reichssportfeld”, 1934–36) and the enthusiasm it triggered in Germany was used by the National Socialist government to present itself, especially to other countries. In 1937, Hitler appointed A. Speer as general building inspector for the “redesign of the Reich capital”. After the Wannsee Conference (20.1.1942) the extermination policy of the National Socialists against the Jews (Holocaust) was pushed. Berlin was also the place where the resistance of church, political and military circles against the National Socialist dictatorship was concentrated (including the Rote Kapelle and the attempted uprising of July 20, 1944, which was planned and directed from the Bendler Block [since 1968 and 1986/89 memorial ]). After the city had suffered severe damage from air raids and area bombings (especially on February 5, 1945) in isolated cases during the war from 1940 and increasingly from November 1943, the encirclement and conquest of Berlin, which had been converted into a fortress (OKW order of March 9, 1945) marked the end Soviet troops in an initially 250 km wide front (16./20.4.–2.5. 1945 »Battle of Berlin« or »Operation Berlin«, among others. bitter street fighting in the urban area of Berlin up to the capitulation of the city on May 2nd) also the military collapse of Germany; Hitler killed himself (April 30th) in the Führerbunker under the New Reich Chancellery (1936–39; Wilhelmstrasse 93), near Potsdamer Platz. The unconditional surrender of the German Wehrmacht in Berlin-Karlshorst (May 8/9, 1945; museum since 1967) officially ended the Second World War in Europe, which had also turned Berlin into a rubble city (over 1 million deaths).
In accordance with the London Protocols (September and November 1944) and the “Four Power Declaration of Berlin” (June 5, 1945), the four victorious powers of the Second World War, the USA, the USSR, Great Britain and France, set up the Allied High Command Berlin (July 11, 1945)) as a joint government body for the four-sector city of Berlin, which, in addition to the highest administrative bodies of the four occupation zones, has equal rights for the special occupation area Greater Berlin, de facto 5th occupation zone, which since 30.7. active Allied Control Council (based in Berlin) was responsible. At the beginning of July, American and British troops occupied the sectors of Berlin (the three Western sectors; 12 urban districts), while the USSR withdrew to the part of the city assigned to it (eastern sector; 8 urban districts).
With the regulation of passenger and freight traffic (September 1945) and the establishment of three air corridors (agreement of October 22, 1945) between the western sectors of Berlin and the western occupation zones of Germany, the western powers and the USSR tried to defuse emerging disputes over western access routes to Berlin.
From the early summer of 1945, political life began to unfold again in Berlin, as dictated by the military authorities and the joint Allied government organs. Supported by the Soviet government, the Ulbricht group, which flown to Berlin on April 30, 1945, tried to influence political events in Berlin – but above all by broadcasting into the Soviet occupation zone (SBZ). On May 19, 1945 the Soviet city commandant of Berlin (Nikolai Bersarin [* 1904, † 1945 ], from April 28, 1945) led a communist-ruled magistrate for all of Berlin under the mayor Arthur Werner (* 1877, † 1967; 1945/46) took office. After the Soviet occupying power had initially supported the organizational independence of the KPD in the course of the formation of new parties (KPD, SPD, CDU, LDP) from June 10, 1945, it promoted the unification of the KPD, especially from the beginning of 1946, under strong administrative pressure and SPD to the SED (in Berlin at SBZ level on April 21/22, 1946). In a strike vote, 80% of the members of the SPD in the western sectors of the city turned against the (immediate) merger. The Soviet city commander forbade voting in the eastern sector.
On the basis of the “Provisional Constitution of Greater Berlin” issued by the Allied High Command Berlin on August 13, 1946, elections were held throughout Berlin on October 20, 1946, in which the SPD 48.7%, the CDU 22.2%, the SED won 19.8% and the LDP 9.3% of the vote. Otto Ostrowski (* 1883, † 1963; SPD) was elected Lord Mayor, after his resignation (April 1947) E. Reuter (SPD; July 1947), who, however, was not allowed to take office at the objection of the Soviet occupying power and until August 1948 was represented by Louise Schröder (SPD), then by F. Friedensburg (CDU). By the Control Council Act number 46 of February 25, 1947 (dissolution of Prussia), Greater Berlin was raised to the rank of a state.
In the course of the increasingly sharp east-west conflict between the Western powers and the USSR, the Soviet representative left the Allied Control Council on March 20, 1948, and on June 16, 1948. also the Allied High Command Berlin; the constitution adopted on April 22nd, 1948 (Berlin as the capital of Germany) was not confirmed by the Soviet city commander. After an agreement on a currency valid for the whole of Berlin had not been reached (currency reform), the Soviet leadership (J. W. Stalin) tried to oust the Western powers from Berlin with the Berlin blockade (June 24, 1948– May 12, 1949); Berlin (West) was over a Western Allied airlift provided. One of the decisive factors for the Western Allied stance on the Berlin and Germany question was the Berliners’ emphatic option for the pluralistic-democratic order of the Western model; Lord Mayor Reuter became one of its worldwide speakers at the height of this first major crisis in Berlin (rally on 9.9.1948). In September 1948, Berlin was finally politically divided into Berlin (West) and Berlin (East).