Bowes-Lyon was killed during the Battle of the Hohenzollern Redoubt in the Battle of Loos. As he led an attack on the German lines, his leg was blown off by a barrage of German artillery and he fell back into his sergeant's arms. Bullets struck him in the chest and shoulder and he died on the field. He was buried in a quarry at Vermelles (), but although the quarry was adopted as a war cemetery, the details of his grave were lost, and so he was recorded among the names of the missing on the Loos Memorial.