London - Three generations of future British kings will gather on Wednesday for the low-key christening of Prince George, the son of Prince William and his wife Catherine.

Current monarch Queen Elizabeth II will also be present for the third-in-line prince's baptism, where she will be joined by heir apparent Prince Charles and second-in-line William.

But the ceremony, to be held at the Chapel Royal in London's St James's Palace, will be hidden from the world's media.

Royal officials have said that only "close members of both families" will attend the baptism, reflecting William and Catherine's belief in keeping their son out of the spotlight.

The service will be conducted by Archbishop of Canterbury Justin Welby, the head of the world's Anglicans, who called it "the next hugely important moment" in the young prince's life.

"A few months ago millions of people around the world celebrated the birth of Prince George," he said in a YouTube message released by his Lambeth Palace office on Tuesday.

"Now we're celebrating the next hugely important moment, which is his christening."

A Church of England christening involves a new baby having holy water poured on its head - the baby is not fully immersed.

George - who is a future Supreme Governor of the Church of England and "Defender of the Faith" - was born on July 22.

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Celebrity photographer Jason Bell - known for his portraits of Beatle Paul McCartney, footballer David Beckham and Hollywood star Scarlett Johansson - has been given sole responsibility for the official pictures.

The award-winning photographer will take the shots at Clarence House, the home of William's father Prince Charles, following Wednesday's service.

The pictures are expected to gain iconic status, showing four generations of monarchs together.

The last time such a photograph was taken was in 1894 at the christening of the future king Edward VIII, showing the infant with his father, later king George V, grandfather, the future king Edward VII, and great-grandmother, queen Victoria.

George has been deliberately shielded from the type of press attention that William blames for the death of his mother, Diana, Princess of Wales, in car crash in Paris being followed by paparazzi.

The new baby's only public appearance has been with his parents as he left the London hospital where he was born.

The only other sighting of George has been in a picture with William, Kate and the couple's dog Lupo which Michael Middleton took in his family's back garden.

This desire for privacy is also highlighted in the "personal decision" to use the Chapel Royal, Diana's former private secretary explained to AFP.

"This is not like a royal wedding for example, this is essentially a private family occasion," said Patrick Jephson.

"All be it, William and Kate have decided to make theirs a very intimate family occasion.

"The location...is different from recent history where baptisms have taken place in Buckingham Palace."

Jephson said that Wednesday's ceremony would send a strong message of the family's durability.

"For the royal family, a christening is important because it shows the continuing survival of the dynasty," he explained.

"It reinforces the public perception that the British royal family is going to be around for a long time to come."

Photos: AFP, Reuters

Click here to read facts on the christening of Britain's royal baby