Simon Douwe Posthuma was born in Zaandam, Holland in 1939. In 1966 he moved to London and was part of the art collective The Fool who gained world fame with their psychedelic designs of record sleeves, posters and fashion for artists such as The Beatles, Bob Dylan, Cream and The Hollies.

In 1968 The Fool signed a record deal with Mercury Records and went to New York where they recorded an album produced by Graham Nash. The Fool then split up but Posthuma went on to record another Nash produced album from which came the hit 'I Saw You'.

Since 1982 Simon has lived and worked in Amsterdam.