He studied with Frank Bridge as a boy and in 1930 entered the RCM. In 1934 he heard Wozzeck and planned to study with Berg, but opposition at home stopped him. The next year he began working for the GPO Film Unit, where one of his collaborators was Auden: together they worked on concert works as well, Auden's social criticism being matched by a sharply satirical and virtuoso musical style (orchestral song cycle Our Hunting Fathers 1936). Stravinsky and Mahler were important influences, but Britten's effortless technique gave his early music a high personal definition, notably shown in orchestral works (Bridge Variations for strings, 1937; Piano Concerto, 1938; Violin Concerto, 1939) and songs (Les illuminations, setting Rimbaud for high voice and strings, 1939).
In 1939 he left England for the USA, with his lifelong companion Peter Pears; there he wrote his first opera, to Auden's libretto (Paul Bunyan, 1941). In 1942 he returned and, partly stimulated by Purcell, began to concentrate on settings of English verse (anthem Rejoice in the Lamb and Serenade for tenor, horn and strings, both 1943). His String Quartet no.2 (1945), with its huge concluding chaconne, also came out of his Purcellian interests, but the major work of this period was Peter Grimes (1945), which signalled a new beginning in English opera. Its central character, the first of many roles written for Pears, struck a new operatic tone: a social outcast, he is fiercely proud and independent, but also deeply insecure, providing opportunities for a lyrical flow that would be free but is not. Britten's gift for characterization was also displayed in the wide range of sharply defined subsidiary roles and in the orchestra's sea music.
However, his next operas were all written for comparatively small resources (The Rape of Lucretia, 1946; Albert Herring, 1947; a version of The Beggar's Opera 1948; The Little Sweep, 1949), for the company that became established as the English Opera Group. At the same time he began writing music for the Aldeburgh Festival, which he and Pears founded in 1948 in the Suffolk town where they had settled (cantata St. Nicolas, 1948; Lachrymae for viola and piano, 1949). And in this prolific period he also composed large concert works (The Young Person's Guide to the Orchestra, 1946; Spring Symphony with soloists and choir, 1949) and songs.
The pattern of his output was thus set, though not the style, for the operas show an outward urge to ever new subjects: village comedy in Albert Herring, psychological conflict in Billy Budd (1951), historical reconstruction in Gloriana (1953), a tale of ghostly possession in The Turn of the Screw (1954), nocturnal magic in A Midsummer Night's Dream (1960), a struggle between family history and individual responsibility in Owen Wingrave (1971) and, most centrally, obsession with a doomed ideal in Death in Venice (1973), the last three works being intermediate in scale between the chamber format of Herring and The Screw, and the symphonic fullness of Budd and Gloriana, both written for Covent Garden. But nearly all touch in some way on the themes of the individual and society and the violation of innocence. Simultaneous with a widening range of subject matter was a widening musical style, which came to include 12-note elements (Turn of the Screw) and a heterophony that owed as much to oriental music directly as it did to Mahler (cycle of 'church parables', or ritualized small-scale operas: Curlew River, The Burning Fiery Furnace, The Prodigal Son, 1964-8).
Many of these dramatic works were written for the Aldeburgh Festival, as were many of the instrumental and vocal works Britten produced for favoured performers. For Rostropovich he wrote the Cello Symphony (1963) as well as a sonata and three solo suites; for Pears there was the Hardy cycle Winter Words (1953) among many other songs, and also a central part in the War Requiem (1961). His closing masterpiece, however, was a return to the abstract in the String Quartet no.3 (1975).
Britten was appointed a Companion of Honour in 1952, to the Order of Merit in 1965, and was awarded a life peerage in 1976.