In 1858, the British government requested permission to raise troops in Canada for service in India. The Canadian colonial government granted the request, and, within three months, a full regiment was raised under the command of Lieutenant-Colonel Baron de Rottenburg, a British officer serving in Canada as adjutant-general of the Canadian militia. The regiment was designated as the 100th Royal Canadian Regiment of Foot. The original 100th Regiment had served in Canada during the War of 1812 and had been disbanded in 1818.
After its service in India, the regiment was later resettled in Ireland, where it was known as the Prince of Wales Lienster Regiment (Royal Canadians) and continued to carry the maple leaf on its regimental badge.
