Born Robert Newton Calvert on 9 March 1945 in Pretoria, South Africa. Calvert's parents moved to England when he was two.

At the end of the 1960s he moved to London and joined the flourishing 'psychedelic' subculture. He soon became one of its most active members; joining, amongst other activities, Frendz, one of the leading underground magazines of the time. During that time he acquainted himself with the "New Wave" of Science Fiction writers. Acclaimed author Michael Moorcock, winner of several Science Fiction literary awards and publisher of the influential New Worlds magazine, became a lifelong friend. Calvert's poems were published in New World and other magazines. Although he was influenced by the New Wave, Calvert developed a distinct style of his own. His ability to change fluently between poetry, music and theatre allowed him to develop into a multimedia artist. Calvert then became acquainted with Dave Brock, and became the resident poet, lyricist and frontman of Hawkwind, intermittently from 1972–1979. Calvert co-wrote Hawkwind's hit single "Silver Machine", which reached #3 in the UK singles chart. Although Lemmy sings on the single version, this is an overdub of a live recording taken at the Roundhouse in London, with Calvert on vocals. "They tried everyone else singing it except me", Lemmy later said. Calvert also directed Hawkwind's live opus, the Space Ritual Tour.