When Henry Allingham's carers told him he had become the world's oldest man, he misheard and replied: “I am just not that tall.”

He soon grasped that he was actually not the world's tallest man but the oldest man and he took the news in his stride.

This is the way Mr Allingham, who died on July 18 at St Dunstan's care home in Ovingdean, Brighton, aged 113, approached life, according to his grandson David Gray.

Today, 16 members of Mr Allingham's family will help celebrate the life of a man who was one of the last surviving First World War veterans, and who spent his latter years trying to educate as many people as possible about what happened during that time.

Most of Mr Allingham's family live in America after his youngest daughter Jean emigrated there and settled down.

Mr Gray, 61, flew in from Michigan at the weekend and has spent the week sorting out his grandfather's affairs.

It was only during the latter years of his grandfather's life that he discovered just what he had been through during the First World War.

He said: “He was a very young grandfather in our eyes. There were times when he appeared younger than my mother.

“He was lively, energetic, loved to sing and play practical jokes and had a positive attitude.

“He always imparted the wisdom he learned in all his years and understood what was good in the world.”

Mr Gray said the publication of his grandfather’s autobiography also helped family members understand what he had been through.

Mr Gray said: “He was encouraged to participate with the First World War Veterans' Association and remind the public about what these men sacrificed.

“He and Dennis Goodwin, from the association, had a tremendous friendship. Henry had faith and trust in his judgement and Dennis made a tremendous investment with his time, watching out for him.”

Mr Gray said when the family saw Mr Allingham at his 113th birthday party in June he was very frail.

He said: “We certainly have grieved over losing him. He had a great life, wonderful experiences and great health.

“He died on his own terms in his sleep which is how I would think we would all like to go.

“Now we have turned from grief to celebration.”

Mr Gray said his grandfather would not like all the attention he will receive at his funeral today.

He said: “He was a shy man but on the other hand, if he thought it was furthering his cause about what the veterans went through in World War One, it's worth doing.

“He had very few requests about his funeral and what would take place. There was just one specific hymn he wanted.

“I would hope the legacy he has left behind would be for people to follow his lead, to be humble, caring and a loving person who looks forward to and enjoys life.”

Mr Allingham's funeral will take place at St Nicholas Church in Dyke Road, Brighton, at midday, today.

He will receive a full public funeral with military honours, which will be attended by mourners, including Her Royal Highness The Duchess of Gloucester, Kevan Jones MP, Under Secretary of State for Defence and Minister for Veterans, Admiral Sir Trevor Soar, Commander-in-Chief for the Fleet of the Royal Navy, and RAF Deputy Commander-in-Chief Personnel, Air Marshal Stephen Dalton.

The cortège will travel from St Dunstan's, Ovingdean, at 11.15am, along the A259 Marine Parade, over the roundabout to Grand Junction Road and King's Road, turning right into West Street, up to the Clock Tower, turning left into Dyke Road, left into Upper North Street, right into Montpelier Street, right into Victoria Road, and into Church Street and Dyke Road.

Dyke Road, which is a cul-de-sac and runs on the north side of the church, will be closed from 9am to allow media vehicles to set up.

Dyke Road, between Upper North Street and Buckingham Road, will be closed from 9.30am to allow for the arrival of guests.

Clifton Terrace will be closed from its junction with Dyke Road, westwards, for 30 metres from 9am, to allow the funeral cortege to assemble with the Guard of Honour The funeral will begin at midday and last until 1pm.

Dyke Road and Clifton Terrace will be reopened at 2pm following the departure of the cortege and guests. Church Street will reopen at about 6pm following departure of the media vehicles.

The Royal Pavilion, which will host the wake, will also be closed to the public until 3.15pm on the day. Admission to the wake is strictly by invitation only.

People can make donations in memory of Mr Allingham to St Dunstan’s (0300 1112233 or online at www.stdunstans.org.uk) and The Dark Horse Venture (0151 2568866).

You can leave tributes to Mr Allingham at theargus.co.uk/allinghamtributes