John graduated M.B., Ch.B. at Glasgow University in 1912 and then for 18 months held appointments as house surgeon in the Western Infirmary and in the Royal Hospital for Sick Children, Glasgow. When war broke out he was resident surgeon at Johannesburg Hospital, resigning the appointment in 1915 to take a commission in the RAMC. John entered the war in France in January 1916, he saw many of the principle engagements on the Western Front during a period of three years. He was doing his work amongst wounded gunners during a battle when he was killed instantaneously. His commanding officer wrote that Capt Teggart was a capable hardworking officer, whose pluck and keenness were well known throughout the division. "He always shone in positions of danger where initiative and true courage were essential" John was the younger twin son of Hamilton Teggart of Glasgow (his twin brother was Lt Francis William Stuart Teggart, who was also killed and served with the Argyll & Sutherland Highlanders). [Information sources: Liz Ross-Bartell, MIC, CWGC and The Lancet]