Prior to 1912, Sharpley enlisted in the Essex Regiment of the British Army. After the outbreak of the First World War, his battalion arrived on the Western Front on 21 August 1914 and saw action at Le Cateau, Marne, Messines and Armentières. Serving as a sergeant, he was mentioned in dispatches and won the Cross of St. George 2nd Class "for conspicuous gallantry in rescuing and bringing in across the open and under fire, a wounded NCO" in late 1914. In February 1916, Sharpley won the Distinguished Conduct Medal for bringing another wounded man in under fire, southeast of Hébuterne. He was killed on the first day of the Somme in an area between Serre-lès-Puisieux and Beaumont-Hamel and is commemorated on the Thiepval Memorial. As a result of his death, Sharpley's sister Kate became an anarchist campaigner.