The Duchess of Cambridge was hoping for a son and her wish has come true, after she gave birth to a baby boy at 4.24pm.
The Duke of Cambridge was present for the birth of his son who weighed 8lbs 6oz.
“Her Royal Highness and her child are both doing well and will remain in hospital overnight,” Kensington Palace said in a statement.
“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.”
The Prince of Wales said that he was “enormously proud and happy to be a grandfather for the first time”, adding that it was “an incredibly special moment for William and Catherine”.
“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.”
It is understood the Queen was informed of the birth in a phone call from William, though the Royal Family will not visit the hospital as it demands an extra level of security which could cause disruption.
Her Majesty arrived back at Buckingham Palace this afternoon after spending the weekend at Windsor Castle.
A beaming 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.”
Confirmation of the Royal birth arrived by car in the form of an official statement, carried by the Duke and Duchess of Cambridge’s press secretary.
The statement, on Buckingham Palace headed paper, was brought out for public inspection on the easel by Badar Azim, a footman with the Royal Household, and Ailsa Anderson, the Queen’s press secretary.
It was signed by the Queen’s gynaecologist Marcus Setchell, who led the medical team that delivered Kate’s baby.
Three were three cheers of “hip hip hooray,” as the crowd outside the palace gates swelled to more than 10 deep.
Many had been waiting patiently for confirmation of the birth ever since news broke of the Duchess going into labour this morning.
Grown men were seen riding on friends’ shoulders, while others used step ladders to get an elevated position.
Kasey Coffee, 21, from Washington in the US, said she had spent three hours queuing ahead of the royal announcement.
“The atmosphere in the crowd was awesome. Everybody was excited, then we heard a shriek that it was a boy – everybody was cheering and jumping. It was an incredible thing to be part of history.”
Police were sent in with the crowds, as many scrambled to get the best vantage point.
But the wait to see the easel, designed to bring an end to a 12-hour vigil at the palace gates for some, proved too much.
One woman left having tried for half an hour to get closer to the front of the crowd, without success. She said: “I’m pleased we tried to see it, but it was just too difficult. It was impossible to get any closer.”
Well-wishers from around the globe rejoiced as news of the birth of the royal baby spread.
Foreign Secretary William Hague added: “My warmest congratulations to the Duke and Duchess of Cambridge.
“Wonderful news and a happy moment for our country and Overseas Territories.”
Canada’s prime minister Stephen Harper sent his “heartfelt congratulations” to the couple and the royal family on behalf of all Canadians.
Outgoing Chief Rabbi Lord Sacks tweeted “Mazal Tov” to the happy couple. ”We wish them blessings, good health, and joy in becoming parents,” he added.
The new royal baby is third in line to the throne and a future king. A great-grandchild to the Queen – her third – the newborn will also one day be crowned sovereign.
If the baby follows after the Prince of Wales and the Duke of Cambridge as king, he will be the 43rd monarch since William the Conqueror obtained the crown of England.
The baby’s uncle, Prince Harry, now moves to fourth in line to the throne, while the Duke of York shifts down to fifth and Princesses Beatrice and Eugenie to sixth and seventh place.