Obstacle or barricade made of felled trees with the branches pointing outwards. Canadian troops used abatises against an American army in the Battle of Châteauguay in October 1813, when the Americans were marching on Montréal.


Officer who assists superior officers by communicating orders and performing administrative duties.

Adjutant General

Senior administrative officer of the Army.


Officer attached to the staff for the personal service of a general.


Shoulder cord first worn by French cavalry in the 17th century. From 1731, a blue and white aiguillette was worn by Canadian officer cadets, which earned them the nickname "Cadet à l’aiguillette". Gold and silver aiguillettes were added to the uniforms of generals and staff officers during the Napoleonic Wars. In Canada, staff officers also wore aiguillettes and they remain part of the uniform for aides-de-camps of the Governor General of Canada and the provincial lieutenant-governors.


Troops transported by air. An idea entertained when the hot-air balloon was invented in the late 18th century, it came under serious consideration with the invention of the parachute and the advent of passenger planes in the 1920s. The first parachute airborne unites were formed by the Soviet Union in 1932. The Germans followed suit in 1936, the French in 1937, the Italians in 1938, and the Japanese, British and Americans in 1940. In 1940-41, German paratroopers participated in successful operations in Europe, and Japanese paratroopers were used in the Dutch East Indies (now Indonesia) in 1942. Canada formed its first parachute troops in 1942 and its 1st Parachute Battalion became part of the British 6th Airborne Division in 1943. Canada was a primary location for paratrooper training during World War II and parachuting has remained a popular skill for Canadian servicemen, identifiable by the parachute's wings badge.

Aircraft carrier

Ship that carries and serves as a base for aircraft. First appearing in the 1920s and 1930s, the ability of aircraft carriers to launch air attacks outside the range of land-based aircraft made them an important part of a fleet. This meant the demise of the battleship, as demonstrated in 1941 when the Bismarck was disabled in the North Atlantic by planes from HMS Ark Royal, the highly successful Japanese air attack on Pearl Harbour and the Battle of Midway where a few American aircraft carriers prevailed over a large Japanese fleet. Small aircraft carriers, called escort carriers, were used to provide air cover against submarines during World War II. The first aircraft carriers manned by Canadians were HMS Nabob and HMS Puncher, loaned to the British Royal Navy by the United States and outfitted primarily with crews from the Royal Canadian Navy. From 1946 to 1969, the RCN had an aircraft carrier in its strength: HMCS Warrior (1946-1948), HMCS Magnificent (1948-1957) and HMCS Bonaventure (1957-1969).


Person serving in the air forces, of any rank and in any capacity.

Alaska Highway

Overland road built in 1942 as a supply line linking the USA and southern Canada to Alaska, in response to Japan's occupation of the Aleutian Islands earlier that year, which threatened west coast shipping. For this reason, and because Alaska was the northern flank of British Columbia and the Yukon, Canada agreed to the construction of the road. Over a nine month period, some 11,000 American troops and 16,000 US and Canadian civilian workers, with approximately 7,000 construction vehicles of all sorts, conquered wilderness, mosquitoes and permafrost bogs to build the 1,523 mile (2,451 km) highway. The corridor to Alaska was administered by the US forces during for the duration of the war, requiring a pass issued by American authorities for anyone travelling on it. The highway was turned over to the Canadian Army in 1946 and remained a military responsibility until 1964. It has since fostered considerable trade and tourism for northern areas.

Allied Expeditionary Force (AEF)

Official title of the Allied armies in the Second World War, including the 1st Canadian Army that invaded France and Northwest Europe in 1944-1945.

Amphibious operations

Military operation launched from the sea with troops embarked in ships or crafts for the purpose of introducing a landing force on a hostile shore. This involves the co-operation of land and sea forces, and, since the 20th century, coverage from air forces. Amphibious operations helped Britain become a world power in the 17th century, using its powerful navy to deploy its relatively small army. The Royal Navy and British Army co-operated in successful amphibious operations in Canada at the sieges of Louisbourg, in 1758, and Québec, in 1759. Aside from some minor engagement during the War of 1812, Canadians were not deployed in such operations until the Second World War, the first being the failed raid on Dieppe. More followed, with success, in 1943 when the 1st Canadian Division landed at Sicily and the 13th Brigade Group landed with the Americans at Kiska, Alaska.

The largest amphibious operation in history is the Normandy landing on June 6, 1944. Canada participated by contributing RCN ships and RCAF squadrons, and securing one of the five landing beaches with approximately 12,000 soldiers. The D-Day assualt remains Canada's largest contribution to this type of operation.


Up to the 16th century, a soldier armed with a bow and arrows. In New France, as in Old Regime France, this name was used to denote a police constable.

Armed merchant cruiser

Merchant ship armed with guns and used as a cruiser during the First and Second World Wars. Being unarmoured and large, they were very vulnerable.


Defensive covering for the body worn in fighting. Early soldiers in Canada wore steel helmets, breast and back plates, and chain mail until the 1630s, when Indian foes began using firearms and armour became ineffective. Metal plates were to used to protect ships starting in the mid-19th century, and motorized land vehicles, such as tanks, have had steel protection in place since the First World War.

Armoured personnel carrier (APC)

Motor vehicle with protective metal plating used to carry troops. Came into common use during the Second World War.


Soldier specializing in the maintenance of weapons. In the early days of New France, armourers could be civilian artisans working remote forts, repairing military, fur trade and hunting muskets.

Arms control

Plan or arrangement governing the numbers or types of weapons in use and the strength or deployment of armed forces (includes disarmament). The first tangible and successful arms control treaty in Canada was the Rush-Bagot Agreement of 1817, which limited the number of American and British warships on the Great Lakes.

See also: Cold War, Nuclear Warfare


Organized force armed for fighting on land. Used as an organizational term during the First and Second World Wars meaning two or more corps under the command of a general, averaging between 120,000 and 200,000 troops of all ranks.

Army group

Organizational term of the First and Second World Wars meaning two or more armies under the command of a field marshal, averaging between 400,000 and one million troops of all ranks (the largest land force formation).


Originally used to describe large guns used in fighting on land and the troops that used them. Now, generally refers to all missile type weapons other than small arms. Artillery arrived in Canada with the 16th century explorers, and many types of artillery were mounted in Canadian forts from the 17th century onward. There were some attempts to cast guns at the Forges du Saint-Maurice in the late 1740s, but it was not until the First World War that artillery was successfully manufactured in Canada.

Automatic weapon

Firearm with a mechanism to load cartridges, fire them, and eject empty casings until ammunition is exhausted or pressure on the trigger is released. First appeared in the late 19th century as machineguns. In Canada, the Gatling machinegun was first used against the Métis at Batoche in 1885.