Son of the late Henry and Mary Rainbow, of Hanslope, Bucks, England. Also served in German South-West Africa and in Egypt. Born in 1890, in Hanslope, Buckinghamshire, England. Walter was the third surviving son of Henry and Mary Rainbow, of Barnwell Buildings, Hanslope, who apprenticed as a railway Coachmaker at Wolverton Carriage Works, Buckinghamshire, before emigrating to South Africa, in the early 1900s, to join his elder brother Henry James Rainbow and his wife Louie at their home in Red Hill, Durban. Whilst in South Africa, Walter enlisted in the colonial regiment, rising to the rank of Sergeant, fighting alongside General Louis Botha's troops, in the German South West Africa campaign 1914-1915. When the African campaign concluded, Walter was entitled to his discharge from service, but honourably, he decided to continue his service, this time for his native homeland, enlisting with the South African Oversea Expeditionary Force on the 24th August 1915, giving up his Sergeant's stripes and returning to England as a plain Tommy Atkins. After a short stay at Bordon Military Camp, Hampshire, he embarked with his regiment from Devonport, Plymouth, on-board HMT Saxonia, 29 December 1915, en route to Marseilles, France via Alexandria, Egypt. Having been promoted to Lance Corporal during his time in England, Walter played a heroic part as a machine gunner in the trenches and with his comrades, engaged in the British troops "push" at the Somme, where, the day before the Battles of Delville Wood and Bazentin Ridge, he sadly met his death. Commemorated on a roll of honour and memorial at the Church of St James the Great, Hanslope, Buckinghamshire.