In 1884, the British government had sent a military expedition under the command of Major-General Charles Gordon to secure the Sudan. The expedition met with determined resistance from a large Muslim army led by the holy man Mahdi. By mid-summer, Mahdi's army had managed to encircle Gordon's force in the city of Khartoum. The British War Office selected Major-General Garnet Wolseley, who had commanded the Red River Expedition in 1870, to lead a force to rescue Gordon's besieged army.
Wolseley had been impressed with the skill and efficiency of the Canadians in transporting his force through a difficult series of rapids and portages to the Red River Settlement. He convinced the Colonial Office to ask the Canadian government to send 300 Canadian "boatmen" and 3 militia officers to the Sudan to transport Wolseley's army up the Nile River. While Prime Minister John A. Macdonald refused to give official assistance to the expedition, he did allow the British to recruit directly from Canada.
Almost 400 boatmen, accompanied by 3 militia officers and an engineer, were sent to the Sudan on civilian contracts. The Canadians managed to transport the large troop boats up the Nile River through dangerous rapids and a series of arduous portages. Wolseley's force, however, arrived too late to save the encircled British force in Khartoum. On 25 January 1885, Mahdi's army took the city and Major-General Gordon was beheaded.