Sidney was born at Forest Gate, Essex, the eldest son of Albert and Emily (nee Johnson) of Ashwell, born on 10 May 1893. He was a pupil at the Merchant Taylors School in Ashwell.
Percy was born on 18 March 1893 at Norton, Hertfordshire, the eldest son of S. Albert and Martha (nee Kitchener) James. He was a pupil at the Merchant Taylors School in Ashwell where they were living when Percy was about 10 years old.
Harry was the third son of Charles Simon and Mary Jane (nee Winter) Wilkins, born at Ashwell, Hertfordshire on 16 June 1893. He was a pupil at the Merchant Taylors School in Ashwell.