There are three works with this name on record, two South African are plays. There is also an American TV series called King of Diamonds (1961–1962)

The King of Diamonds by Harold J. Laite (1953)

The original play

Written as a three-act play by Harold J. Laite, dealing with Cecil John Rhodes (1853-1902) [1] and Barney Barnato (1851-1897) [2]. It was published by Pioneer Press in Cape Town in the 1956.

South African performances

1953: First presented at the Labia Theatre, Cape Town, 1953.

Sources

Text of The King of Diamonds, University of Stellenbosch Library Catalogue.

The King of Diamonds, a film treatment by Stephen Sondheim

According to Stephen Banfield (1993), Stephen Sondheim also did a film treatment called The King of Diamonds with Larry Gelbart in 1954. No trace of such a film can be found however.

Sources

Stephen Banfield, 1993, Sondheim's Broadway Musicals (p. 27)[3],

The King of Diamonds - the musical by Bob O'Keefe, and Edgar Adeler

The text

Possibly based on Harold J. Laite's play, The King of Diamonds is a musical play with Barney Barnato (1851-1897) [4] as central figure and hero, with a book by Bob O'Keefe, music by Edgar Adeler.