At the outbreak of the Second World War, Boulton, who was already with the Essex Yeomanry, joined the Royal Horse Artillery and served in North Africa.
In 1940 he took part in Operation Compass, fighting at the Battle of Bardia and then the Siege of Tobruk, where he contracted jaundice and was evacuated to Alexandria.
[1] He spent much of the rest of the war recovering in Cairo, where he met his future wife Margaret Elizabeth Hunter.
After the war he left the army as a lieutenant colonel and was employed with the Allied Control Council, helping to re-establish the German legal profession while excluding those members with Nazi sympathies.
Shortly before his retirement in 1975, Boulton was heavily involved in the establishment of the Senate of the Inns of Court and the Bar, which handles internal disciplinary matters.