Finland and Germany were both at war against the Soviet Union from June 25 1941 until Finland entered into an interim peace agreement with the Soviet Union in September 19 1944. Marshall Mannerheim was the commander-in-chief of the Finnish defence forces during the war. The 4th of June 1942 was Mannerheim's 75th birthday. Hitler decided he wanted to pay Mannerheim a visit on his birthday which was arranged on a very short notice. There were no negotiations between Hitler and the Finnish government or Mannerheim. The visit did have some implicit political significance but its overt purpose was to be a social call only.
Mannerheim, Hitler, the president of Finland Ryti and prime minister Rangell were sitting at a table on the restaurant car of Mannerheim's private train that was parked on an industrial side track near Immola Airfield where Hitler's plane had landed. The conversation was secretly recorded by Thor Damen, a YLE technician. Hitler never allowed anyone to record his conversation off guard. Hitler's SS bodyguards did catch Damen in the act but they did not confiscate the tape, only stopped the recording. Since then the tape has been in YLE archives.
There is a YouTube video containing the entire 11 minute recording with English subtitles.
