[2] Simpson was born in Suffolk on 27 March 1909[3] and educated at Merchant Taylors' School, Crosby and at Trinity Hall, Cambridge.

[6] He was placed on half-pay due to ill-health on 13 April 1936,[7] and returned to full duty, but with reduced seniority, on 15 July 1936.

He was landed in France at 0900 on D-Day in command of 26 and 80 Assault Squadrons, Royal Engineers, in the "Nan Red" sector of Juno Beach.

The task of these squadrons, which had only been formed three months previously, was to clear exits through the defences at the top of the beach so that the largely Canadian forces landed there could breakout into the country beyond.

Initially he was a secretary to the Joint War Production Committee of the United States and Canada,[14][15] and then from August 1952 he was responsible for briefing the UK NATO representatives on those issues.