It is not every grandfather who tells tales of almost asking King George V for a job after bumping into him in Hyde Park.

But then, as he celebrates his 110th birthday today, it is clear Britain's oldest World War One veteran, Henry Allingham, is not like every other grandad.

His family - ranging in age from 58 years to six weeks old - have flown over from America for the special occasion so it is clear meeting royalty is not the highlight of his life.

Mr Allingham sat in the private section of the Grand Hotel in Eastbourne yesterday with a broad grin on his face.

He said: "I can't believe it. They have come here to see me. These boys here - my grandchildren.

"They are getting on a bit, some of them are over 50. I can't believe I have grandchildren who are nearly retired. They are all good kids and they have been kind."

Mr Allingham was married to his wife, Dorothy, for 53 years, They had two daughters, Jean and Betty.

He was joined by Jean's four boys, David Gray, 58, Paul Gray, 54, Timothy Gray, 50, and Christopher Gray, 46.

Paul said: "It's an honour to share his 110th birthday. The last time this many of the family were together was on his 100th birthday and we celebrated here in the Grand then.

"At that time, his daughter, Jean, our mother, was still alive. It's amazing how alert he is and how healthy he looks. He doesn't look much different to the last time we saw him and that was a couple of years ago.

"We have been planning this trip since the end of last year. Chris was able to join in the celebrations at HMS Belfast last week. It was nice he could represent the family and one of us could witness it."

Paul was accompanied by his wife, Melanie, and Christopher by his wife, Diana, and their daughter, Sara Trapp, 25, and her husband, Clayton.

David was joined by his son, Nathaniel, 30, his wife, Janna, and daughter, Amy, 35, her husband, Chris Carlson, 37, and their children, Lauren, almost two, and six-week old Eric, Mr Allingham's great-great grandchildren.

They were also joined by Mr Allingham's carers and friends Dennis and Brenda Goodwin, from Worthing, who are never far from his side, having shared many memories.

Mrs Goodwin said: "He has a wonderful memory. When the war finished he was always out on his bike trying to find work. He took a short cut through Hyde Park and bumped into King George V.

"He has met most of the royal family and remembers six monarchs and Queen Victoria's funeral."

Mr Allingham was born on June 6, 1896, in Clapton, East London, and began his military career as an air mechanic second class on September 21, 1915.

After graduating, he was posted to the Royal Naval Air Service air station at Great Yarmouth. He then joined the armed trawler Kingfisher, which was involved in the biggest naval battle of the Great War, the Battle of Jutland in 1916.

Last week he visited HMS Belfast in London as guest of honour for the Ghosts Of Jutland exhibition and to see a hologram image of himself.

Mr Allingham said: "I joined up thinking it would be an adventure but my ship was nearly sunk by a German shell at Jutland. I was one of the lucky ones."

He recalled seeing shells ricocheting across the sea and said: "There was a lot of dud shells and that saved us from a lot of harm. You don't have much time to think. You've got a job and you get on with it and make sure you play your part to the best of your ability. People ask if was frightened but you don't have time to be frightened."

He transferred to the newly formed RAF on April 1, 1918, and remained in the service until he was discharged in 1919.

He married Dorothy Cater in Chingford, Essex, shortly afterwards.

He had met her in Great Yarmouth outside a church before he was sent abroad and walked her home.

Mr Allingham said: "I remember seeing Dorothy for the first time and after plucking up the courage that was that. I never had another girl and we were married 53 years."

As well as being Britain's oldest First World War veteran, he is the last founder member of the RAF and the sole survivor of the Battle of Jutland.

To commemorate their comrade, the RAF has organised a fly-past today in Eastbourne.

Two Tornadoes from No 31 Squadron are expected to fly over the hotel as dignitaries, relatives and Mr Allingham look on.

Mr Allingham will later enjoy a private lunch with his family and friends.

Mr Goodwin, founder of the First World War Veterans' Association, said: "It's going to be a tremendous day for Henry.

"He has been asked so many times in the last few months what it feels like to be such a grand age. He really does marvel at the fact he has reached the age he has and I know he is looking forward to Tuesday."

Mr Allingham has been recognised for his efforts during the war on many occasions.

He led the nation in the Lord's Prayer at the Cenotaph in London to commemorate the 90th anniversary of the outbreak of the First World War.

He then travelled to France for Armistice Day to lay a wreath at a British memorial in St Omer where he was made a freeman and unveiled a plaque to commemorate the heroism of all First World War flyers.

In 2003, he was awarded The Legion d'Honneur, France's highest decoration.

In April, he was given the freedom of Eastbourne, the town he moved to in 1964 with his wife after many holidays there.

He lived in the same house until three weeks ago, when due to his deteriorating eyesight, he moved to St Dunstan's, a care home for ex-servicemen and women, in Ovingdean, near Brighton.

During 110 years, he has witnessed many occasions and inventions but thinks the aeroplane is the greatest.

He said: "It brings families and people together and ultimately we will all be one.

"It will take a long time to get there but it will come."

Asked about his secret for long life, he replied: "It's one of those things. I think it's because I have kept within my limits.

"If you don't enjoy it, quit.

"How do I feel about being 110? Ask me tomorrow."