The Unknown War (Russian: "Великая Отечественная" (The Great Patriotic War) or "Неизвестная война" (The Unknown War) is an American documentary television series. The 20-part series documents the World War II conflict between Nazi Germany and the Soviet Union. The show was produced and syndicated for international distribution by Air Time International, and the executive producer was Fred Weiner. Each episode is about 48 minutes long, similar in format to the film The World at War. The footage was edited from over 3.5 million feet of film taken by Soviet camera crews from the first day of the war during Operation Barbarossa on 22 June 1941 until the Soviet entry into Berlin during the Battle of Berlin in May 1945. Most of these films have never been seen outside this documentary series.