Earnest Prosser was an underground colliery worker from Blackwood, the son of Frederick and Charlotte Prosser. He answered the call early in the conflict, deploying overseas and arriving in France in January 1915 to join the veteran 2nd Battalion, Welsh Regiment, operating as part of the British 1st Division.

In late September 1916, his division was heavily engaged in the Battle of Flers–Courcelette—the final general British offensive of the tragic Somme campaign. Although the main coordinated attack was officially called off on 22 September, intense artillery duels and localized front-line adjustments continued to tear up the ground between Albert and Bapaume over the subsequent days.

Private E Prosser (10145) was killed in action during these fierce sector holdouts on 23 September 1916, aged 26. Because his resting place could never be recovered from the pulverized Somme landscape, he is commemorated on the historic Thiepval Memorial, France. His name is permanently engraved alongside more than 72,000 others who fell in the Somme Sector and have no known grave.