Born in Yorkshire, Blythe studied drama on scholarship at the Royal Academy of Dramatic Art after serving in the Royal Air Force. He began his professional career as a repertory player with the Living Theatre Company, the Nottingham Playhouse, and the Royal Shakespeare Company. He made his West End debut in 1965.
Selected Theatre Credits
- The Creeper (St. Martin's Theatre, 1965): Maurice
- Early Morning (English Stage Company/Royal Court, 1969): Lord Mennings
- So What About Love? (Criterion Theatre, 1969): Robert
- Absurd Person Singular (Criterion Theatre, 1974): Sidney
- The Clandestine Marriage (Savoy Theatre, 1975): Sir John Melvil
- The Return of AJ Raffles (Royal Shakespeare Company/Aldwych Theatre, 1975): Lord Alfred Douglas
- The Chairman (Globe Theatre, 1976): Peter Frame (Clarence Derwent Award)
- Sextet (Criterion Theatre, 1976): Roger
- Caught in the Act (Garrick Theatre, 1981): Bill Taylor
- The Hard Shoulder (Aldwych Theatre, 1983): David
- Number One (The Queen's, 1984): Bernard
- Pravda (National Theatre/Olivier Theatre, 1985): Michael Quince, MP
- The Government Inspector (National Theatre/Olivier Theatre, 1985): Artemy Zemlyanika
- Futurists (National Theatre/Cottesloe Theatre, 1986): Lenin/Romanov
- Woman in Mind (Vaudeville Theatre, 1986): Bill
- The Living Room (Royalty Theatre Company, 1987): Michael Dennis
- Julius Caesar (Compass Theatre Company, UK national tour, 1990): Cassius
- The Hothouse (Chichester Festival Theatre; The Comedy, 1995): Lobb
- Hedda Gabler (Chichester Festival Theatre, 1996): Judge Brack
- Peter Hall Company at the Old Vic, 1997: Waste (Sir Charles Cantilupe, MP), The Provok'd Wife (Lord Rake), King Lear (Duke of Albany)
- Flight (National Theatre/Olivier Theatre, 1998): Commander in Chief of the White Army
- Hay Fever (Savoy Theatre, 1999): David Bliss
- Hamlet (Royal National Theatre, US national tour and some UK performances, 2001): Polonius/The Grave-digger
- The Royal Family (Theatre Royal Haymarket, 2001): Gilbert Marshall
- Mrs. Warren's Profession (Strand Theatre, 2002): Mr. Praed
- Humble Boy (Gielgud Theatre, 2002): Jim
- Henry V (National Theatre/Olivier Theatre, 2003): Duke of Exeter
Film and television
Blythe worked in films only rarely and usually in minor roles; his most substantial part was also in his last film appearance, The Luzhin Defence (2000). Other film credits include two movies for Hammer Film Productions, A Challenge for Robin Hood (1967) and Frankenstein Created Woman (also 1967); his most successful film was Carrington (1995).
By contrast, Blythe appeared in several dozen television series, miniseries, and movies, most notably as Samuel Ballard, QC in Rumpole of the Bailey (1983–92). He guest-starred in episodes of The Avengers, UFO, Callan, New Scotland Yard, Special Branch, Agatha Christie's Partners in Crime, Agatha Christie's Poirot, Inspector Morse, Maigret, The Inspector Alleyn Mysteries, Between the Lines, Pie in the Sky, Goodnight Sweetheart, Dalziel and Pascoe, and Foyle's War (aired posthumously), among many others. His miniseries appearances included The Barchester Chronicles, After the War, and The Alan Clark Diaries. He narrated the 1970 TV comedy special Cucumber Castle starring The Bee Gees.
Blythe lived for eight years with Harriet Walter; the couple were planning to marry at the time of his death.