David J. Rees was a local coal miner, the son of David and Naomi Rees of Markham Crescent, Oakdale. He enlisted into the 9th (Service) Battalion, Welsh Regiment, which operated as part of the 19th (Western) Division. Early in his front-line service, he was wounded in action but successfully recuperated in Britain before bravely returning to active duty on the Western Front.

In the late summer of 1917, his division was thrown into the meat-grinder of the Third Battle of Ypres (Passchendaele), engaging in fierce, muddy assaults against fortified German lines. Private Rees sustained severe combat wounds during these intense operations and was evacuated via ambulance trains down to the massive British base hospital complex in Normandy.

He tragically succumbed to his injuries on 24 September 1917, aged just 21. He is buried at Saint Sever Cemetery Extension, Rouen, France, resting alongside thousands of other casualties who passed away in the nearby military hospital wards.