Manning was born in 1882 in Sydney, Australia, and whose father was a one-time mayor. Educated privately, he was thereafter sent to England to complete his studies.
In the immediate pre-war years Manning established a reputation as a minor poet and critic among a small circle of intimates.
With the outbreak of war in August 1914 Manning enlisted as a Private with the 7th Battalion King's Shropshire Light Infantry, serving in the trenches in France among some of the more bloody battles of the war.
In 1929 Manning anonymously published in a private edition his novelised memoirs of the war, The Middle Parts of Fortune, in two volumes. In place of his name he simply listed his army serial number.
The following year, 1930, an expurgated edition of the book was commercially published as Her Privates We - without the strong language deemed likely to offend a wider readership.
Manning wrote no more fiction, retiring instead into scholarly seclusion. He died in London in 1935; it was a further eleven years before he was finally identified as the author of the war classic hailed by Hemingway as "the finest and noblest book of men in war I have ever read".
T.E. Lawrence (of Arabia) observed that "no praise could be too sheer for this book ... it justifies every heat of praise. Its virtues will be recognised more and more as time goes on."