Julius Caesar is a film .
The film stars Marlon Brando as Mark Antony , James Mason as Brutus , John Gielgud as Cassius , Louis Calhern as Julius Caesar , Edmond O'Brien as Casca , Greer Garson as Calpurnia , and Deborah Kerr as Portia .
Julius Caesar -LRB-1953 film-RRB-