Lieutenant-Colonel Armstrong was born in Swan River, Manitoba; however, attended and graduated from secondary school in Castlegar, British Columbia. He entered Royal Roads Military College in 1976 and graduated from the Royal Military College in 1981 with a Bachelor of Science degree. Posted to the Third Regiment, Royal Canadian Horse Artillery in Shilo, Manitoba, Lieutenant-Colonel Armstrong was employed over the next three years in all junior officer field battery positions. This posting included a UN tour to Cyprus in 1982. In 1984, he was appointed the Battery Captain of the regiment’s air defence battery, and then, in 1985, was posted to England to attend the Gunnery Staff Course (Air Defence) at the Royal School of Artillery, Larkhill. Upon return to Canada in 1986, Lieutenant-Colonel Armstrong was posted as an Instructor-in-Gunnery at the Air Defence Artillery School in Chatham, New Brunswick. In 1989, Lieutenant-Colonel Armstrong was posted as Staff Officer Survival-to-Operate with 1 Air Division Headquarters in Lahr, Germany. In 1990, on promotion to Major, he was attached as a Battery Commander with the 22nd Air Defence Regiment, Royal Artillery in Dortmund, Germany. In 1992, he moved with his regiment to England and completed his battery commander tour at the end of that year. Following a short posting with the Canadian Defence Liaison Staff (London), Lieutenant-Colonel Armstrong was posted to Headquarters Land Force Command, St-Hubert, Quebec in 1993 as a staff officer in the G3 Artillery section. In 1994, he completed a tour with the European Community Monitor Mission in Bosnia and Croatia. In 1995, Lieutenant-Colonel Armstrong attended the Canadian Forces Command and Staff College in Toronto, Ontario and upon graduation was posted as the Second-in-Command of 11 Field Regiment, Royal Canadian Artillery in Guelph, Ontario. In 1997, he completed a tour as a J3 Co-ordination staff officer with the Stabilization Force Headquarters in Sarajevo, Bosnia. Lieutenant-Colonel Armstrong was appointed Commandant of the Canadian Forces Nuclear, Biological and Chemical School in Borden, Ontario in 1999. In this position, he was also the Commanding Officer of the Joint Nuclear, Biological and Chemical Response Team, responsible for responding to NBC terrorism in Canada. In 2002, he became the Operations Officer for the Canadian Forces Support Training Group in Borden. Lieutenant-Colonel Armstrong was appointed Commanding Officer of 11 Field Regiment, in Guelph, Ontario in June 2004. In 2006 he was posted as the Commanding Officer of Regional Cadet Support Unit (Central), in Borden, until his retirement from the Regular Force in 2011. Upon his transfer to the Reserve Force, Lieutenant-Colonel Armstrong was appointed as Commanding Officer of 3 Canadian Ranger Patrol Group, in Borden, in 2011. Lieutenant-Colonel Armstrong assumed his current appointment, once again as Commanding Officer of 11 Field Regiment, in April 2014. .