Warren acted as British Field Marshal Bernard Montgomery’s Canadian aide-de-camp and personal assistant, while ‘Monty’ lead his famous 8th Army—which defeated the Germans and General Rommel at El Alamein, then chased them across North Africa to their surrender in Tunisia.
Warren was in Montgomery’s conference tent when five German officers signed the surrender at Lüneburg Heath, Germany. As personal assistant to Montgomery, Warren was the man who fetched the Germans to Montgomery’s caravan on May 3, 1945 to hear Monty’s terms, and on May 4 to sign the surrender. More surrenders followed on May 7, prior to VE Day on May 8. In 1945, Warren was made a military Member of the Order of the British Empire (O.B.E.) and received the American Bronze Star medal for his liaison work between the British 8th and American 5th Armies over dangerous war fields in Italy.
With the end of the war, Warren organized Rheem Canada Limited in Hamilton, which made steel drums, then hot-water heaters. He ran the company from 1946 to his retirement in 1976. He became honorary colonel of the 48th Highlanders from 1973 to 1976, and had a long association with the Royal Winter Fair, becoming president in 1974.
He was on the Board of Argus Corporation, Hollinger Inc. and Hendrie and Company and was a president of Ancaster’s Tamahaac Club, where he was a skeet sharpshooter. In the 1960’s, Warren built a country home called Corwhin Acres—named after a local railway intersection—in the Guelph area. There, his pride and joy was the huge evergreen forest he planted and watched grow over 35 years. He died in Guelph on September 12, 2001.