Hitler transferred his headquarters to the "Führerbunker" ("Leader's bunker") in Berlin on 16 January 1945, where he (along with Bormann, his secretary Else Krüger, and others) remained until the end of April. The "Führerbunker" was located under the Reich Chancellery garden in the government district of the city centre. The Battle of Berlin, the final major Soviet offensive of the war, began on 16 April 1945. By 19 April the Red Army started to encircle the city. On 20 April, his 56th birthday, Hitler made his last trip to the surface. In the ruined garden of the Reich Chancellery, he awarded Iron Crosses to boy soldiers of the Hitler Youth. That afternoon, Berlin was bombarded by Soviet artillery for the first time. On 23 April, Albert Bormann left the bunker complex and flew to the Obersalzberg. He and several others had been ordered by Hitler to leave Berlin.