 Yamashiro was completed on 31 March 1917 and assigned to the 1st Division of the 1st Fleet in 1917 – 18, though she had no combat role in World War I. Like her sister, she patrolled off the coast of China during the war and assisted during the Great Kanto Earthquake. Little detailed information is available about her activities during the 1920s, although she did make a port visit to Port Arthur, China, on 5 April 1925 and also conducted training off the coast of China. Yamashiro became flagship of the Combined Fleet in 1935. In early 1941, the ship experimentally launched radio-controlled Kawanishi E7K2 floatplanes.
