THE Duke and Duchess of Cambridge have spent the night with their baby son.

The baby weighed 8lbs 6oz and was born at 4.24pm.

The palace said in a statement: ''Her Royal Highness The Duchess of Cambridge was safely delivered of a son at 4.24pm. The baby weighs 8lbs 6oz.

''The Duke of Cambridge was present for the birth.

''The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall, Prince Harry and members of both families have been informed and are delighted with the news.

''Her Royal Highness and her child are both doing well and will remain in hospital overnight.''

A Buckingham Palace spokesman said: ''The Queen and Duke of Edinburgh are delighted at the news.''

Locally, the mayor of Christchurch, Cllr John Lofts, wished the Royal couple well on behalf of the borough.

“I’m just glad all appears to have gone well. I wish the same as everyone else, that everybody’s well and the child has a long and happy life," he said.

The mayor of Poole, Cllr Philip Eades, said: “We’re delighted that mother and baby are doing well and we offer them our fullest congratulations.”

Soon after the palace announcement was made, a notice giving details about the baby - the third-in-line to the throne - left St Mary's Hospital in London by car for Buckingham Palace.

It has been signed by the Queen's former gynaecologist Marcus Setchell, who led the medical team that delivered Kate's baby.

The notice will be placed on an easel in the palace's forecourt just like the announcement of William's birth on June 21, 1982, a traditional element of theatre in marked contrast to the modern age of emails and Twitter.

The new royal baby will be the Queen's third great-grandchild and is destined to be crowned monarch.

He will be the 43rd sovereign since William the Conqueror if, as expected, it follows reigns by the Prince of Wales then William.

The Prince of Wales issued a brief statement: ''Both my wife and I are overjoyed at the arrival of my first grandchild. It is an incredibly special moment for William and Catherine and we are so thrilled for them on the birth of their baby boy.

''Grandparenthood is a unique moment in anyone's life, as countless kind people have told me in recent months, so I am enormously proud and happy to be a grandfather for the first time and we are eagerly looking forward to seeing the baby in the near future.''

Moments before Charles's joyous words were released the Queen's press secretary Ailsa Anderson strode out onto Buckingham Palace's forecourt to place the official notice on its ornate stand.

The document had four signatures, first was that of Marcus Setchell, Surgeon Gynaecologist to Queen, who led the medical team that delivered Kate's baby.

Other members of his team included Guy Thorpe-Beeston, obstetrician and Dr Sunit Godambe, consultant neonatologist at St Mary's Hospital.

Kensington Palace said ''The names of the baby will be announced in due course.''

David Cameron declared the birth ''an important moment in the life of our nation''.

Speaking outside 10 Downing Street, the Prime Minister said: ''It is wonderful news from St Mary's, Paddington and I am sure that right across the country, and indeed right across the Commonwealth, people will be celebrating and wishing the royal couple well.

''It is an important moment in the life of our nation but, I suppose, above all it is a wonderful moment for a warm and loving couple who have got a brand new baby boy.

''It has been a remarkable few years for our royal family - a royal wedding that captured people's hearts, that extraordinary and magnificent jubilee and now this royal birth - all from a family that has given this nation so much incredible service.''

''They can know that a proud nation is celebrating with a very proud and happy couple tonight.''

President Barack Obama said in a statement: ''Michelle and I are so pleased to congratulate The Duke and Duchess of Cambridge on the joyous occasion of the birth of their first child.

''We wish them all the happiness and blessings parenthood brings. The child enters the world at a time of promise and opportunity for our two nations.

''Given the special relationship between us, the American people are pleased to join with the people of the United Kingdom as they celebrate the birth of the young prince.''