This Modern Classics edition celebrates the play's fortieth anniversary, with a foreword by Antonia Fraser and an introduction by Michael Billington.

Harold Pinter's Betrayal received its premiere at the National Theatre, London, in November 1978. After an initially guarded response from the critics, the work was rapidly reevaluated and won the Olivier Award for Best New Play the following year. Set in London and Venice the play has an innovative chronology that opens at the end of an affair and works its way backwards over nine years, from 1977 to 1968. It is widely considered one of the playwright's pivotal works.