World War One is an American documentary television series that was shown on CBS during the 1964–1965 television season to commemorate the fiftieth anniversary of the start of the war. The series was produced by CBS News, which featured 26 half-hour episodes, was narrated by Robert Ryan. World War One originally aired on Tuesday nights at 8 pm Eastern Time, but at mid-season it was moved to Sunday nights at 6:30 pm because it was being beaten in the ratings by the second half-hour of ABC's Combat! and the second half-hour of NBC's Mr. Novak. Re-released in 1995, the series is available on video tape and DVD but no US video-on-demand services have it.