Born in Redruth, Cornwall, to Gerald, a solicitor, and his wife, Jeanne (nee Vollar), Peter was the third of seven siblings. His father died when Peter was young, and the family relocated to Brixton, south London, and later Surrey. During this period he showed an early talent for acting in Scout Association Gang Show stage productions, which led to a number of roles in repertory theatre, including Pip in Great Expectations opposite Donald Sutherland.