At Ypres, the Battalion were tasked with the capture of the Pilckem Ridge – a heavily fortified German defensive line during the Battle of Passchendaele.

His citation read: At Pilckem, Belgium, on 31st July 1917, an enemy machine gun inflicted many casualties when it opened fire at close range.

Sergeant Rees, leading his platoon, gradually worked his way round the right flank, by making short rushes, to the rear of the gun position.

He bombed a large concrete emplacement, killing five of the enemy and taking 30 prisoners, including two officers and capturing a machine gun, undamaged.During the Second World War, he served as a Company Sergeant-Major in the Home Guard.

Rees is remembered on memorials in Havard Chapel, Brecon Cathedral and at Llanelli Town Hall, Carmarthenshire.