Gloriana, Op. 53, is an opera in three acts by Benjamin Britten to an English libretto by William Plomer, based on Lytton Strachey's 1928 Elizabeth and Essex: A Tragic History. The first performance was presented at the Royal Opera House, London, in 1953 during the celebrations of the coronation of Queen Elizabeth II. Gloriana was the name given by the 16th-century poet Edmund Spenser to his character representing Queen Elizabeth I in his poem The Faerie Queene. It became the popular name given to Elizabeth I. It is recorded that the troops at Tilbury hailed her with cries of "Gloriana, Gloriana, Gloriana", after the defeat of the Spanish Armada in 1588.
The opera depicts the relationship between Queen Elizabeth and the Earl of Essex, and was composed for the coronation of Queen Elizabeth II in June 1953. Several in the audience of its gala opening were disappointed by the opera, which presents the first Elizabeth as a sympathetic, but flawed, character motivated largely by vanity and desire. The premiere was one of Britten's few critical failures, and the opera was not included in the series of complete Decca recordings conducted by the composer. However, a symphonic suite extracted from the opera by the composer (Opus 53a), which includes the Courtly Dances, is often performed as a concert piece.