Corin's first stage appearance was at the Royal Court in 1961 as Lysander in Tony Richardson's production of A Midsummer Night's Dream. Immediately afterwards he played the Pilot Officer in John Dexter's production of Wesker's Chips with Everything at the Royal Court, The Vaudeville, and the Shubert Theater in New York. He joined the Royal Shakespeare Company in 1972 for a season at Stratford and at the Aldwych, playing Octavius in Julius Caesar and Antony and Cleopatra and Antipholus of Ephesus in The Comedy of Errors. At the Young Vic Corin has played Rosmer in Rosmersholm, Danforth in The Crucible, Brutus, Angelo, Coriolanus, and Major Howard in Les Smith's Some Kind of Hero with Trevor Etienne. In 1993, he took part in the World Poetry Festival at Pittsburgh, USA, with his sister Vanessa, Kika Markham, and Mikhail Shatrov in a programme of Russian Poetry, "A Cloud in Trousers." He is a founding member of Symposium 90, an international association researching the origins and consequences of Stalinism. In the cinema he worked with some great directors, including Richardson, Roeg, Zinneman and Christine Edzard, in whose brilliant study of Victorian plutocracy and poverty The Fool, he played Sir Thomas Neathouse. Corin starred as Dixon in Jim Sheridan's Name Of The Father and played Andie MacDowell's husband in the Mike Newell film Four Weddings And A Funeral.