Harper was 28 years old, and a corporal in the 4th Battalion, York and Lancaster Regiment, British Army during the Second World War when the following deed took place for which he was awarded the VC.

On 29 September 1944 during an assault on the Depot de Mendicite, Merksplas, Belgium, Corporal Harper led his section across 300 yards of completely exposed ground, with utter disregard for the hail of mortar bombs and small arms fire from the enemy.

In North-West Europe, on 29th September, 1944, the Hallamshire Battalion of the York and Lancaster Regiment attacked the Depot de Mendicite, a natural defensive position surrounded by an earthen wall, and then a dyke, strongly held by the enemy.

Corporal Harper then left his platoon in charge of his senior section commander and walked alone along the banks of the dyke, in the face of heavy spandau fire, to find a crossing place.

His magnificent courage, fearlessness and devotion to duty throughout the battle set a splendid example to his men and had a decisive effect on the course of the operations[1]His Victoria Cross is held at The York & Lancaster Regiment Museum in Rotherham, South Yorkshire, England.

51°6′44.17″N 5°16′6.47″E / 51.1122694°N 5.2684639°E / 51.1122694; 5.2684639 A stained glass window, created by Frans Pelgrims and donated by the town of Merksplas (Belgium) as sign of an everlasting gratitude and respect, depicting Corporal Harper and the area of his final battle are shown in Hatfield St Lawrence Church.