Peter John Sinfield (27 December 1943 – 14 November 2024) was an influential English poet, songwriter, and musician, renowned for his contributions to the progressive rock genre. Born in Fulham, London, Sinfield's early life was marked by a love for literature and poetry, which he developed during his education at Danes Hill School and Ranelagh Grammar School. After a brief stint as a travel agent and work in the computer industry, he pursued his passion for music and poetry, eventually forming a band called the Creation.

Sinfield is best known as a co-founder and lyricist of King Crimson, where he played a crucial role in crafting the band's distinctive sound and image. His surreal and imaginative lyrics were a defining feature of King Crimson's early albums, including their groundbreaking debut, "In the Court of the Crimson King." Sinfield's artistic vision extended beyond lyrics; he was instrumental in the creation of the iconic album cover for the band's debut, collaborating with artist Barry Godber.

After his tenure with King Crimson, Sinfield continued to leave his mark on the music industry. He worked with notable acts such as Emerson, Lake & Palmer (ELP), Roxy Music, and the Italian band PFM. His work with ELP included providing lyrics for albums like "Brain Salad Surgery" and "Works, Volumes I & II." In the realm of pop music, Sinfield co-wrote successful hits for artists including Celine Dion, Cher, Cliff Richard, and Bucks Fizz.

Sinfield's contributions to music were recognized by his peers and critics alike. He was described as the "premier littérateur of Progressive" by Paul Stump and hailed as a "prog rock hero" by Q magazine. Despite his success, Sinfield remained a figure who preferred to work behind the scenes, often referring to himself as a "maker of kings."

In his later years, Sinfield retired to the Suffolk coast, where he enjoyed cooking and gardening. He briefly reunited with Robert Fripp in 2014 to update the lyrics for King Crimson's "21st Century Schizoid Man." Sinfield passed away in November 2024 at the age of 80, leaving behind a legacy of artistic innovation and lyrical brilliance that continues to influence the music world.