Born in Outremont, Quebec, Canada on the 17th April 1919 to Treffle Lamontagne and Marie Anna Édesse Kieffer.

Joseph Lamontagne married Mary K. Schaefer and had 1 child.

studied at Collège Jean-de-Brébeuf, where he met Pierre Trudeau, then at the École des Hautes Etudes Commerciales. At 22, he enlisted in the Royal Canadian Air Force during the Second World War.

His Wellington bomber was shot down over the Netherlands in 1943, and he remained a prisoner of war for 26 months, until May 1945. For the full story of the incident here.

He ended his air force service with the rank of flight lieutenant.

He settled in Quebec in 1945 where he owned an import business for 20 years. He entered municipal politics in 1962 and was then mayor of Quebec from 1965 to 1977.

That year, he joined the Trudeau cabinet and was elected to the House of Commons in a by-election. First Postmaster General, he was then Minister of National Defense until 1983. In 1984 he was appointed Lieutenant-Governor of Quebec, a position he held until 1990.

Decorated with the Order of Canada in 1990 , Gilles Lamontagne will be made Knight of the National Order of Quebec in 2000.

He passed away on the 14th June 2016 age 97 in Québec, Canada. The funeral was held at the Basilique-Cathédrale of Notre-Dame de Québec.