The discovery took place as a group from the school travelled to see WWI Battlefields of the Somme in northern France.

Jack Parkin (13) of Hatfield Woodhouse, laid a poppy cross on the grave of his great, great, great uncle, Private J Smeaton from The King's Own Yorkshire Light Infantry, who died on March 27 1916 to the south of the town of Arras.

A school spokesman said: "It was quite a moving experience for Jack, who found the information through the Commonwealth War Graves Commission website."

Another 13-year-old, Christain Caddy, found the grave of his great grandfather, Sergeant C Caddy, who is buried at Dartmoor Cemetery, near Thiépval. Sgt Caddy was killed in September 1916.

Four students also laid a wreath at the Menin Gate ceremony in Ypres, where The Last Post is played every evening at 8pm in memory of the dead of World War I

This year's visit was Hatfield Visual Arts College's tenth trip, and on each occasion students have laid a wreath at the Menin Gate.

Each year also, one or two students take the opportunity to visit a relative's grave on behalf of their family.