The Canadian Secretary of State for External Affairs, Lester B. Pearson, announced that the Canadian government would send three Royal Canadian Navy (RCN) destroyers to Korea. The HMCS Cayuga, Athabaskan and Sioux left Esquimalt B.C. under the command of the captain of the Cayuga, Captain Jeffry Brock. 5 July 1950. The Canadian government officially placed the force under the command of the American commander of the UN forces in Korea, American General Douglas MacArthur 14 July 1950.
On 7 August 1950, Canadian Prime Minister Louis St. Laurent announced that Canada would send an infantry brigade to join the UN forces in Korea. The brigade was given the designation the “ Canadian Army Special Force” (CASF). At the time the Canadian Army field force, known legally then as the Active Force, consisted of just three battalions of infantry in the MSF. It was not acceptable to denude the country of its only standing army units so a new brigade of three infantry battalions was to to be raised. It would be composed of newly raised (2nd) battalions of the Princess Patricia's Canadian Light Infantry (PPCLI), the Royal Canadian Regiment (RCR), and the Royal 22e Régiment Royal 22nd Regiment (R22eR). The brigade commander was Brigadier J.M. Rockingham.
The brigade assembled at Fort Lewis, Washington State. While there the CASF was re-designated as the 25th Canadian Infantry Brigade (CIB). While the brigade was still at Fort Lewis, the UN forces had launched an offensive 15 September 1950. The North Korean Army retreated to the north, and it appeared as though the Korean conflict was almost over. As a result, the Canadian government initially decided to send only the PPCLI . On 18 December, the PPCLI arrived in South Korea. It was intended that troops committed to Korea would be there for one year and therefore recruits were enrolled for an 18 month period of service. To provide replacements, each of the three infantry regiments raised a third battalion for eventual rotation to Korea. This process started shortly after the 2nd battalions had been raised. The initial replacement of the battalions in Korea however was the 1st Battalions, the MSF. To ensure the continuation of the defence of Canada, a company of parachutists was excluded from the rotation to Korea and a certain number of troops were sent back to Canada from the battalions in Korea to take parachute training.
Concurrent with the Korean contingent girations the army was raising a NATO brigade to be stationed in Germany to face the threat of Soviet aggression in Europe. In the case of the original Korean contingents the militia had been a major source of manpower. Over 200 ex-members of the Loyal Edmonton Regiment, for example, including some very key officers and NCOs, volunteered for service in Korea with 2PPCLI. But in the case of Germany the militia was used in a very direct manner. Companies of volunteers were formed from various militia units across Canada and put into composite battalions called, colourlessly, 1st Canadian Infantry Battalion, 1st Canadian Rifle Battalion, and 1st Canadian Highland Battalion. The Loyal Edmonton Regiment,for example, recruited rifle companies for both the 1st and 2nd Infantry Battalions. (When a soldier moved from one company to another he would go have to get a complete change of buttons and badges from the his new company's quartermaster stores!) Replacement battalions for NATO also had to be raised for these as well since initial NATO service too was to be on a year basis. So in addition to 1PPCLI, 2PPCLI, and 3PPCLI, and similarly for the RCR and the R22eR, we have by about 1952 1st and 2nd Infantry Battalions, 1st and 2nd Rifle Battalions, and 1st and 2nd Highland Battalions -- the army had expanded between 1950 and 1953 from 3 to 15 infantry battalions! By about 1954 the composite battalions became 1st and 2nd Battalions of the Canadian Guards, the Queen's Own Rifles, and the Black Watch (Royal Highland Regiment) of Canada. About 1954 3RCR and 3PPCLI became 3rd and 4th Canadian Guards (although this was largely nominal : the 3rd and 4th Guards located in Valcartier were to be bilingual or unilingual Francophone units). By 1957 it was determined that Canada's army needed more armoured units to confront the threat of Soviet tank forces in North West Europe so 3 and 4 Cdn Gds were re-designated as the The Fort Garry Horse and 8th Canadian Hussars. Initially Canada's NATO brigade had a reconnaissance squadron and a single tank squadron but now had a full armoured (tank) regiment.