Royal Wedding is a 1951 MGM musical comedy film starring Fred Astaire and Jane Powell, with music by Burton Lane and lyrics by Alan Jay Lerner. The film was directed by Stanley Donen; it was his second film and the first he directed on his own. It was released as Wedding Bells in the United Kingdom.
The story is set in London in 1947 at the time of the wedding of Princess Elizabeth and Philip Mountbatten, Duke of Edinburgh. Astaire and Powell are siblings in a song and dance duo, echoing the real-life theatrical relationship of Fred and Adele Astaire.
Royal Wedding is one of several MGM musicals that lapsed into public domain on their 29th anniversary due to failure to renew the copyright registration.
(Summary from Wikipedia)