During the early morning of Oct. 25, 1893, a column of 700 soldiers from the British South African Police camped in a defensive position next to the Shangani River. While they slept, the Matabele king Lobengula ordered an attack on the column, sending a force of up to 6,000 men—some armed with spears, but many with Martini-Henry rifles. Among its weapons, the column possessed several Maxim machine guns. Once a bugler sounded the alert, the Maxims spun into action—and the results were horrific. The Maxim gunners mowed down more than 1,600 of the attacking Matabele tribesman. As for the British...