Editing Dornford Yates (section)

==The Great War and afterwards==
At the outbreak of the [[World War I|Great War]] in 1914, Mercer was commissioned as Second Lieutenant in the [[3rd County of London Yeomanry (Sharpshooters)]],<ref>{{London Gazette|issue=28941|supp=y|page=8330|date=17 October 1914}}</ref> although his stories continued to appear in the ''Windsor'' until March 1915. In 1915, his regiment left for [[Egypt]] and, in November 1915 as part of the 8th Mounted Brigade, he was sent to the [[Macedonian front (World War I)|Salonika/Macedonian front]] where the war was in stalemate. Suffering severe [[muscular rheumatism]] he was sent home in 1917 and, although he was still in uniform, the [[War Office]] did not again post him. He eventually left the army in 1919. In June of that year the ''Windsor'' carried his first story since the end of the war.

Since 1914, the Mercer family home had been Elm Tree Road, behind the north-west side of [[Lord's Cricket Ground]] in [[St John's Wood]], where his friends Oscar and Lily Asche were close neighbours. In autumn of 1919, he and Asche combined to write the stage show ''Eastward Ho!'', but the production was not a great success and he did not again attempt to write for the stage.  A frequent social – and then romantic – Elm Tree Road visitor was Bettine (Athalia) Stokes Edwards, an American girl who danced in ''Chu Chin Chow'' (and daughter of Robert Ewing Edwards of Philadelphia, Pennsylvania) who became Mercer's first wife.<ref name="Who Was Who 1960">''Who Was Who'' (1960)</ref> ''The New York Times'' announcement of their engagement (28 August 1919) states: "Mr & Mrs Glover Fitzhugh Perin of 57 West Fifty-eight street have announced the engagement of Mrs Perin’s oldest daughter Miss Bettine Stokes Edwards. . . ." suggesting that her father either was dead or divorced; her remarried mother then lived in New York City. Mercer and Bettine married at [[St James's, Spanish Place]], in the [[Marylebone]] district of London, on 22 October 1919. The month of October also marked the appearance of a story in the ''Windsor'' called ''Valerie'' whose female lead made a living as a dancer; this story never appeared in book form.

Mercer decided not to return to the bar, and to concentrate on his writing. He and Bettine lived in Elm Tree Road, where their only child, Richard, was born on 20 July 1920. After the Great War, many ex-officers found that the rise in the cost of living in London precluded maintaining the style of life of a gentleman to which they had become accustomed; some looked beyond England. In 1922, the Mercers emigrated to France, where it was possible to live more cheaply, and where the climate was kinder to Mercer's [[muscular rheumatism]].