McNeile, Herman Cyril: Michael Cassidy, Sergeant. v1. 26 Dec 2015
 

Herman Cyril McNeile, MC (28 September 1888 – 14 August 1937), commonly known as Cyril McNeile and publishing under the name H. C. McNeile or the pseudonym Sapper, was a British soldier and author. Drawing on his experiences in the trenches during the First World War, he started writing short stories and getting them published in the Daily Mail. As serving officers in the British Army were not permitted to publish under their own names, he was given the pen name "Sapper" by Lord Northcliffe, the owner of the Daily Mail; the nickname was based on that of his corps, the Royal Engineers.

Excerpt
Michael Cassidy is sergeant in His Majesty’s Corps of Royal Engineers, to which I also have the honour to belong in the humble capacity of officer. I say humble advisedly; for there are sergeants of many sorts and kinds, and there is Michael Cassidy, and in his presence even Director Generals have trembled.