The composer Philip Heseltine (1894-1930), better known by his pseudonym ‘Peter Warlock’, is one of the most fascinating characters in twentieth-century English music. Educated at Eton and Oxford, yet musically largely self-taught, he is considered by many to be one of the great English song-writers. But besides being a composer, he was also an important pioneer editor of early music as well as the author of a number of books and numerous articles for newspapers and journals. His eccentric life-style, his outspoken comments and writings about music, as well as the mysterious circumstances surrounding his death, have all ensured that the ‘Warlock legend’ has not lost its fascinationover the years. During his short life he was a prolific and highly articulate letter writer and some thousand of his letters have survived. These the Warlock scholar and authority Barry Smith has edited with copious annotations and footnotes as well as generous background material.