County of York under the Militia Act of that year; 1st Troop redesignated 27 April 1866 as The Governor General's Body Guard for Upper Canada; Redesignated 1 July 1867 as The Governor General's Body Guard for Ontario; Reorganized 5 May 1876 as a two troop squadron; 1st Troop (Oak Ridges) and 2nd Troop (Markham) of the 2nd Regiment of Cavalry amalgamated 17 May 1889 with the Body Guard to form the full regiment; Redesignated 13 July 1895 as The Governor General's Body Guard; Amalgamated 15 December 1936 with The Mississauga Horse and redesignated as The Governor General's Horse Guards; Converted 11 February 1941 to armour and redesignated as the 2nd (Reserve) Regiment, The Governor General's Horse Guards; Redesignated 1 April 1941 as the 3rd (Reserve) Armoured Regiment (The Governor General's Horse Guards); Redesignated 4 February 1949 as The Governor General's Horse Guards (3rd Armoured Regiment); Redesignated 19 May 1958 as The Governor General's Horse Guards The Mississauga Horse Originated 1 April 1903 in Toronto, Ontario as the Toronto Light Horse Redesignated 22 December 1903 as the 9th Toronto Light Horse Redesignated 1 May 1907 as the 9th Mississauga Horse Redesignated 15 March 1920 as The Ontario Mounted Rifles Redesignated 1 April 1924 as The Mississauga Horse Amalgamated 15 December 1936 with The Governor General's Body Guard Lineage chart Perpetuations Militia Units The Markham Troop The Oak Ridges Troop The Governor General's Body Guard The Mississauga Horse The Great War 4th Battalion, Canadian Mounted Rifles CEF 7th Canadian Mounted Rifles, CEF 216th Battalion (Bantams), CEF Alliances – The Royal Canadian Dragoons – The Blues and Royals (Royal Horse Guards and 1st Dragoons) – 1st The Queen's Dragoon Guards Operational history War of 1812 The Markham Troop, perpetuated by the Regiment, was raised in 1810 as the first Cavalry troop in the colony. The Troop was raised for the York Volunteer Infantry. When the Town of York population expanded the Battalion was split into three new Battalions in 1812 just in time for the war. The Markham Troop was assigned to the 1st York Regiment and designated the York Troop of Horse. Its soldiers served at several engagements including Detroit, Queenston Heights and the Battle of York. The Regiment was given a War of 1812 Banner in 2012 to commemorate the Troops participation in this conflict on the 200th Anniversary of the War. The 1837 Rebellion When Mackenzie's rebels marched onto Toronto