The Billie Whitelaw character is based on Caitlin McNamara, the wife of Dylan Thomas. The American critic and academic, played by Barry Morse, is based on John Malcolm Brinnin, Thomas' biographer, and the stern Dr. Saunders, played by Cyril Cusack, is based on D.J. Thomas, the poet's father.
The character of "Hugh Saunders" was based on Dylan Thomas, but, although he is played by a Welsh actor, Sir Anthony Hopkins, the character is said to be Irish. Also, the play ends with the poet celebrating his fortieth birthday, which Thomas never reached.