One of Smith's first actions during the war was to commandeer all ships on Lake Nyasa and launch an attack upon the German vessel "Hermann von Wissmann" at Sphinx Hafen. On 20 August 1914 Smith mobilised the Nyasaland Volunteer Reserve which defended the colony from a German invasion and later served elsewhere in the East African campaign. After the 1915 Chilembwe uprising, which he moved swiftly to quash, Smith noted that it marked "a new phase in the existence of Nyasaland" and established a commission to investigate its causes. Smith was granted responsibility for administering the former German East African territories occupied by British forces advancing from Nyasaland and sent many of his civil servants into these areas.