For the first time this thesis traces the history of the Oxford Playhouse from its beginning to the present day. I call it Agamemnon and After... the 'lost cause' that became the Oxford Playhouse because it was a production of Aeschylus's tragedy in 1880 by a student, Frank Benson, later one of Britain's foremost Shakespearean actor-managers, which led - fortuitously - to the theatre's launch in 1923. Since J.B. Fagan staged the first successful production of Chekhov in England in 1925 most directors have contributed to Britain's dramatic heritage. Even the happy-go-lucky Stanford Holme, who took the Playhouse downmarket in the 1930s, has his niche in history for taking theatre to the people during the Second World War. A few, like Peter Hall, have achieved international stature. Yet the Playhouse itself, though historians often mention it in the same breath as pioneers of the repertory movement like Birmingham and Liverpool, has never received full recognition - in part because its own records before 1956 have vanished, in part because of its ambivalent relationship with Oxford University. By leafing through old journals, collecting documentary evidence, including missing programmes, and interviewing as many people as I can, I have pieced together the story of the last 83 years. It has many surprising twists, but most fascinating, and complex, is the role the university has played, or rather failed to play. Central to my thesis is the contention that even from 1961 to 1987, when the Playhouse was the University Theatre, it was an ill-starred partnership: as I put it when I was Oxford Mail theatre critic, a shotgun marriage that ended in a messy divorce.