Frederick Lonsdale (5 February 1881 – 4 April 1954) was a British playwright known for his librettos to several successful musicals early in the 20th century, including King of Cadonia (1908), The Balkan Princess (1910), Betty (1915), The Maid of the Mountains (1917), Monsieur Beaucaire (1919) and Madame Pompadour (1923). He also wrote comedy plays, including The Last of Mrs. Cheyney (1925) and On Approval (1927) and the murder melodrama But for the Grace of God (1946). Some of his plays and musicals were made into films, and he also wrote a few screenplays. Source: Wikipedia (en)