Canadian Army General. As a military officer, he served in the Second Boer War and World War I. Born of Scottish descent, he received his education at Trinity College School, Port Hope, Ontario, and graduated from the Royal Military College of Canada in June 1886 and became a lieutenant in the Canadian Militia. He received a commission in the Royal Artillery but resigned for personal reasons prior to joining. In September 1889 he exchanged into the Canadian North-West Mounted Police and commanded the C Division and the Battleford District, later becoming Adjutant of the whole force. In January 1900, during the Second Boer War, he volunteered into the 2nd Battalion Canadian Mounted Rifles for service in South Africa at the rank of captain, and was promoted to major the following May. During his service in South Africa, he was awarded a Distinguished Service Order award for his actions. After returning to Canada, he rejoined the Canadian North-West Mounted Police and was promoted to superintendent. As a lieutenant colonel, he served as Commanding Officer of the Lord Strathcona's Horse (Royal Canadians) armored regiment, during the periods March 1907 to April 1910 and April 1912 to December 1915. In May 1915, during World War I, he took his unit to France and in December of that year, he was promoted to the rank of brigadier general and became commander of the 7th Canadian Infantry Brigade. Later, he commanded the 1st Canadian Infantry Division, and was promoted to the rank of major general. He was referred to by his men as "Fighting Mac" or "Batty Mac," because of his eccentricities in combat under fire. He was awarded the Order of Knight Commander, The Most Honourable Order of the Bath (military division) for his gallantry during World War I. From 1919 until 1925 he was appointed the first Canadian Commandant of the Royal Military College (RMC) of Canada at Kingston, Ontario. He retired from the Canadian Army in 1925 and was promoted to the rank of lieutenant general in recognition of his years of service. From May 1922 until his death, he was Honorary Colonel to Lord Strathcona's Horse. He died at the age of 72. The Sir Archibald Macdonell Athletic Centre, which opened in 1974 at the RMC is named in his honor. His personal Coat of Arms were carved on the Currie Building at the RMC.