During the early stages of the war, enlistment for military service was low, as most British in Hong Kong at the time were professionals or businessmen. By early 1915, there were only 47 volunteers. In 1917, the colonial government introduced the Military Service Ordinance, requiring all males to serve in various capacities. This led to the formation of the Hong Kong Defence Corps. The Hong Kong Defence Corps took over garrison duties, and the regular garrison was freed for service in Europe. By the end of the war, almost a quarter (579 out of 2,157) of the British male population volunteered outside Hong Kong for military services. Chinese residents also joined the Chinese Labour Corps, serving in France and Mesopotamia.
