Walter was born in 1894 into a Quaker family living in Lemington-on-Tyne, Northumberland. He was educated at the Quaker Ackworth School, and then was an agricultural student until he volunteered in May 1915 for the Friends’ War Relief Victims Service. He served with them in France until August 1915, then in October 1915 he transferred to the Friends’ Ambulance Unit, also in France. A month later, on 28 November, he was killed by a German bomb in Flanders. He is buried in Malo-les-Bains Commmunal Cemetery, Nord, 1 A, Grave 4A.

His younger brother, Andrew Isaac Messer, born in 1895, also educated at Ackworth and then a student at Edinburgh University, volunteered or the FAU in August 1915, and served in France until December 1918.