John Gielgud was born in Kensington, London, and had a head start in the theatrical profession, being a great-nephew of Ellen Terry. He trained at RADA and his initial success was as a stage actor, in classical roles. He starred and directed in many Royal Shakespeare Company productions at Stratford-upon-Avon. His Hamlet of 1936 was particularly admired.
Although he began to appear in British films as early as the 1930s, he would not make an impact in that medium until the last decades of his life. His film roles included: Benjamin Disraeli in The Prime Minister (1940), Cassius in Julius Caesar (1952), and George, Duke of Clarence to Laurence Olivier's Richard III (1955). Unlike Olivier, he remained primarily a stage actor, therefore the rivalry between them was minimal.
As he aged, Gielgud began to adapt more to changing fashions in the theatre, appearing in plays by Harold Pinter. In the 1980s and 1990s, it was jokingly said that he was prepared to do almost anything for his art. In 1981, he won an Academy Award for his supporting role in the comedy, Arthur, starring Dudley Moore, and his performance in Shine (1996) was critically acclaimed.