The son of a British mother and an American father, Sir John was raised in England. As a young man he moved to Scotland, and upon the outbreak of World War II he enlisted in the Gordon Highlanders. He was later commissioned in the Black Watch. He served as a paratrooper and later a member of the Special Allied Airborne Reconnaissance Force. His marriage to Esther Driver du Pont brought him to live in the countryside of southeastern Pennsylvania, where over decades he developed extensive English-style gardens at the couple’s estate, Doe Run. An acclaimed horticulturalist, he produced a clear yellow lily called Clivia Sir John Thouron that was put on the market only when the commercial nursery agreed to donate some of the profits to the Thouron Award. His lifelong contributions to British-American relations were recognized when he was knighted aboard the royal yacht Britannia on the occasion of Queen Elizabeth II’s 1976 visit for the bicentennial of American independence.