After nationalist sentiments fuelled a lengthy period of rioting in 1959, the Belgian government granted independence to the Congo on 30 June 1960. Within a week, Congolese troops mutinied against their primarily White officers and refused to recognize the authority of the new civilian government. The mineral-rich province of Katanga declared itself independent, and civil strife engulfed the country.The new president of the Congo, Patrice Lumumba, appealed to the United Nations (UN) for assistance. The UN Security Council met on 13 July 1960 and the next day approved the formation of a UN force to establish order and supervise the withdrawal of the remaining Belgian troops from the Congo. The Organisation des Nations Unies au Congo (ONUC) was established under the command of a Swedish officer, General Carl von Horn.
Two Royal Canadian Air Force transport squadrons were committed to the operations. They conducted an airlift of refugees from the Congo to Europe and transported supplies for the ONUC forces deploying in the Congo. The Number 57 Canadian Signal Unit arrived in the Congo on 2 September 1960 with a complement of 280 officers and men. It received a very rude welcome. Congolese troops beat the Canadian soldiers with rifle butts as the latter debarked from their aircraft. Canadian signallers arrived armed only with Sterling 9mm SMGs. As a result of this incident, the signals detachments were rearmed with 7.62mm FNC1 and FNC2 rifles and anti-tank rocket launchers. An infantry officer, disguised as a Royal Canadian Signal Corps officer, was placed with the 10-man detachments dispersed throughout the Congo. French-speaking officers were required, which meant that most were from Le Royal 22e Régiment. Another consequence was that the Signal Corps ceased training its own recruits at the Royal Canadian School of Signals, Barryfield, Ontario (near Kingston). Instead, it sent its recruits to infantry depots, generally the Royal Canadian Regiment Depot, Wolseley Barracks, London, Ontario.
The scope of the UN peacekeeping operation in the Congo pushed the definition of that term to the limit. Not only did the UN mission end up having to help rebuild a government infrastructure for the new country, but it also went to war to reintegrate the breakaway province of Katanga into the country. This operation, directed by a Security Council resolution of 24 November 1961, saw the ONUC mount a large infantry division advance into Katanga to disarm the mercenary "gendarmes" that were trying to maintain the rebel government in power. The UN suffered 245 military and 5 civilian fatalities in the four years that the ONUC operated. Most of the fatalities were suffered in the Katanga operation. Two Canadian soldiers were among the fatalities.
The final months of UN involvement saw many small operations to rescue people caught in the ongoing civil strife. Several Canadians were awarded medals for bravery during a major UN operation to rescue missionaries. Lieutenant-Colonel Paul Augustus Mayer of The Regiment of Canadian Guards was awarded the George Cross for an incident on 28 January 1964. During a helicopter extraction of several missionary priests and nuns, he refused to leave his post until all the missionaries had been evacuated. Sergeant Joseph Alex Leonce Lessard of Le Royal 22e Régiment was also awarded the George Cross for another helicopter extraction that occurred the next day. Lessard single-handedly rescued two nuns in a village that was being overrun by insurgents. After throwing both nuns into the helicopter, he himself jumped aboard when it was already lifting off, pursued by a hail of spears and arrows. As well, Brigadier J.A. Dextraze, the UN chief of staff in the Congo, was made a commander of the Most Excellent Order of the British Empire for his "superb leadership and control during the missionary rescue operations." These operations are credited with saving the lives of over 30 missionaries and students. Earlier in the UN involvement in the Congo, Lieutenant Terrence Liston, a member of Le Royal 22e Régiment and one of the infantry officers assigned a signals detachment, had been awarded the MBE (Member of the Most Excellent Order of the British Empire) for saving the life of a wounded Congolese lying in a minefield.By the summer of 1963, the fighting in the Congo had subsided. On 30 June 1964, the last Canadian troops in the Congo returned to Canada.