John de Chastelain was born a British subject in Bucharest, Romania, in 1937. He was educated in England and Scotland, immigrated to Canada in 1955, and joined the Calgary Highlanders as a Private in January 1956. In September, he attended the Royal Military College, and graduated in 1960 with Honours in History. He was commissioned into the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI).
John had postings with the 1st and 2nd Battalions of the PPCLI, including tours as a Company Commander in West Germany and Cyprus. In 1962, he was appointed Aide-de-Camp to the Chief of the General Staff in Ottawa. Following postings to Staff College at Camberley, England, and Edmonton, Cyprus, Calgary and Winnipeg, where he commanded 2PPCLI, and a year in the Federal Bicultural Program at Laval University, he became Senior Staff Officer on the Militia's Regular Support Staff in Quebec.
As Commander of CFB Montreal in 1974, John's mandate was to prepare the Base for the 1976 Olympic Games. Following an appointment as UN Deputy Chief of Staff and Commander of the Canadian Contingent in Cyprus, on promotion to BGen, he was appointed Commandant of RMC. After three years at RMC, having sworn in the first class of Lady Cadets, he commanded the 4th Canadian Mechanized Brigade Group in Lahr. In 1982, he was Director General of Land Doctrine and Operations. A year later, he was promoted to MGen, and became Deputy Commander of Force Mobile Command in St. Hubert, QC. He returned to Ottawa as a LGen to be ADM Personnel and Vice Chief of the Defence Staff.
In 1989, John was promoted to General and appointed Chief of the Defence Staff (CDS). During his tenure, the Cold War ended and the events at Oka and the First Gulf War took place, budget cuts in defence reduced the national deficit, the troops stationed in Germany were withdrawn, and operational commitments in Yugoslavia and elsewhere increased. In 1993, John was appointed Canada's eighteenth Ambassador to the United States. He took office the day before President George Bush handed over to President Clinton. When Prime Minister Mulroney resigned, the new PM chose his own Ambassador to the U.S.A., and asked John to return as CDS.
In 1995, John agreed to a two-month mandate from the British and Irish governments to join a three-man International Commission to examine the issue of paramilitary arms in Northern Ireland. He subsequently retired from the Canadian Forces and, since 1996, he has worked with international bodies on the Northern Ireland peace process, initially as International Independent Chairman of the Northern Ireland Multi-Party Talks, which led to the Good Friday Agreement of April 1998, and, since September 1997, as Chairman of the Independent International Commission on Decommissioning. In the fall of 2005, after many years, John succeeded in the seemingly impossible mission of getting the IRA to decommission its weapons, for which he was recommended for the Nobel Peace Prize.
Since his retirement, John has participated as a Senior Advisor to the University of Windsor's Jerusalem Old City Initiative, a member of the Canadian Delegation on the Forum of Federations (of which Canada is the leading nation), a member of the Board of Directors of the United Nations Association in Canada, a member of an International Committee of Experts assembled to advise the Government of Mexico on security issues, Vice-President and member of the Board of Directors of the Conference of Defence Associations Institute, and a member of the Board of Governors of Commissionaires Canada.
John is an Officer of the Order of Canada, Commander of the Order of Military Merit, Companion of Honour (U.K.), Commander of the Order of St. John, Commander of the Legion of Merit (U.S.A.), and has the Medal of Merit and Honour of Greece. In 1992, he received the Vimy Award. He has received honorary doctorates from six Canadian universities, and is an Honorary Fellow of Lady Margaret Hall College, Oxford. He has been President of the Dominion of Canada Rifle Association, Vice-President of the National Rifle Association (U.K.), National Vice-President of Scouts Canada, and Colonel of the Regiment of the PPCLI.
Infantry Officer, RMC Commandant, Chief of the Defence Staff, celebrated statesman, international peace negotiator, piper.