On 15 September 1916 at Ginchy, France, during the Battle of the Somme, Lieutenant Colonel Campbell took personal command of the third line when the first two waves of his battalion had been decimated by machine-gun and rifle fire. He rallied his men and led them against the enemy machine-guns, capturing the guns and killing the personnel. Later in the day he again rallied the survivors of his battalion and led them through very heavy hostile fire. His personal gallantry and initiative at a very critical moment enabled the division to press on and capture objectives of the highest tactical importance.