John Keen was born in 1919 to Edmund and Sylvia Keen in Cheltenham, Gloucestershire. He was married to Marjorie Keen of Swansea.

Sergeant John Keen had only been with the Sherwood Rangers for a week, when on 21 January 1945, his Sherman went into action as part of C Squadron attacking Selsten, Germany. His was one of four Sherman tanks lost by C Squadron that day, John being killed as he and his crew bailed out of their tank. He was 26 years old.

John was buried in Sittard War Cemetery, Limburg, The Netherlands in plot E.4., his headstone bearing the inscription ‘Deep in our hearts Your memory is kept’.