THE 85-year-old son of the youngest soldier to have fought in World War I will be a guest of honour at the national children's WWI remembrance concert.

Sidney Lewis was just 12-years-old when he enlisted with the East Surrey Regiment and fought at the Battle of the Somme when he was 13.

His age was only revealed when his mum contacted the War Office and demanded that he be sent home.

And his children only found out about his wartime experiences after his death.

Sidney's son, Colin, 85, lives in Sandbanks and has been invited to the Lest We Forget concert in Birmingham with his two sons.

Performers at the concert will include pupils from Parkstone Grammar School who turned Sidney's story into an original musical composition after Colin shared his story with the school.

They worked with Music in Action and the Soundstorm Music Service to create the piece, which will be performed at the NEC in Birmingham on November 3.

Colin told the Daily Echo: "We had no idea about my father's story until long after he died. I recall him talking about serving in World War I once but I just thought it was fanciful because I knew he wouldn't have been old enough."

The Director of the concert, Dr Ron Dawson, issued the personal invitation after hearing of the story of Sidney and Colin.

On the first day of the Battle of the Somme it is estimated that 38,000 British soldiers were killed and Sidney fought in the Battle of Delville Wood, which saw some of the worst casualties on the Somme.

However, he survived the carnage. After hearing from his mother, The War Office discharged Sidney and he was sent home.

Although it is known that World War I recruiters turned a blind eye to those under age, Sidney was tall and heavily-built for his age and may not have aroused suspicion.

His story appeared in a national newspaper on September 18 1916.

Sidney enlisted again when he reached the official age of 18. To mark his service he was awarded the Victory and the British War Medals.

In later years he served with the army of occupation in Austria before joining the police in Kingston Upon Thames.

He served in bomb disposal in World War II and later ran a pub in East Sussex. He died in 1969.

His story was largely unknown until around five years ago when a distant relative sent a collection of documents to Colin. Colin has since donated the papers to the Imperial War Museum.

He also speaks in schools and added: "The children are always very surprised when they find out what he did at the age of 12."