The Gang of Four

Described by Baxter and Barnes as the gang of four, left to right, Peter Purves, Lesley Judd, Valerie Singleton and John Noakes. 

Valerie Singleton joined Blue Peter on 3 September 1962 and left on 3 July 1972

John Noakes joined Blue Peter on 30 December 1965 and left on 26 June 1978

Peter Purves joined Blue Peter on 16 November 1967 and left on 23 March 1978   

Lesley Judd joined Blue Peter on 5 May 1972 and left on 12 April 1979

Whilst there was only a period of two months where all four of the gang appeared together in the studio on a weekly basis, Valerie Singleton continued to be an associate or roving presenter on Blue Peter for many years including the production of the Blue Peter Assignment spin-off series up to 1981. In his Blue Peter 50th Anniversary book, Richard Marson said that "Singleton never really left Blue Peter".