Complex sentence: In 1939, Fred and Ginger only made one movie, The Story of Vernon and Irene Castle which ended their partnership for 10 years, until they reunited for The Barkleys of Broadway.
Split into simpler sentences: In 1939, Fred and Ginger only made one movie, The Story of Vernon and Irene Castle. It was the end of their partnership for ten years, until they reunited for The Barkleys of Broadway.