Walter Armstrong was a highly qualified pharmaceutical chemist at the time he left New Zealand to join a leading pharmacy in London. At the outbreak of the war he applied for a position in the British army as a dispenser. There were a thousand applicants for the ten positions advertised, one of which he secured.

The date of Trooper Armstrong's death is uncertain, but may have been in May 1900.

Before World War I, enteric fever, or typhoid fever, was the scourge of armies, and in the Anglo-Boer War killed more soldiers than enemy action. It is caused by a bacteria entering the body via contaminated food or water. Early symptoms include high fever, headaches and lassitude. Follicles along the intestinal walls later become inflamed, often leading to perforation and hemorrhaging. Other complications include gall bladder, pneumonia or heart failure.

At the time of the Boer War, there were no antibiotic remedies for the disease. AWMM