He and Ian McKellen, who have both played Gandalf, also share the same middle name of Murray.
He and brother Peter were educated at Brighton College.
He appeared in three different adaptations of Charles Dickens's 1843 novel "A Christmas Carol". He played Jacob Marley in both Scrooge (1951) and A Christmas Carol (1971) (TV) and Ebeneezer Scrooge in A Christmas Carol (1977) (TV).
He was awarded the 1988 London Critics Circle Theatre Award (Drama Theatre Award) Special Award.
He was awarded the Knight Bachelor of the Order of the British Empire in 1983 for his services to drama.
Made his professional debut in 1937 at the People's Palace, east London, playing Lodovico in "Othello". Later in the year he joined the repertory company of the Little Theatre in Bristol; it was here that he met his future wife, actress Eve Mortimer. They had one daughter.
Notable stage work for the Royal Shakespeare Company in Stratford and in London, at the Old Vic and in the West End. In addition to his many Shakespearean roles (As You Like It, Julius Caesar, Hamlet, Twelfth Night), Hordern performed in plays by Strindberg, Chekhov, Ibsen, Pinero, Pinter, Dürrenmatt, Albee, Alan Ayckbourn, David Mercer and Tom Stoppard. His King Lear is considered his most respected work, which he also played on the BBC.
On the Wogan chat show he said he refused the offers to play the second Doctor Who (played by Patrick Troughton) and Maigret (played by Rupert Davies).