William and Kate show new prince to the world

The Duke and Duchess of Cambridge have introduced their new son to the world.

The prince was born at the Lindo Wing of St Mary's Hospital in Paddington at 11.01am on St George's Day.

His birth was officially announced two hours later and a formal notice placed on a golden stand in front of Buckingham Palace, as is tradition.

Weighing 8lb 7oz, he is expected to be named in the next few days, with Arthur being the bookies' favourite.

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The Duke of Cambridge was at his wife's side as she gave birth and left for just a short while later in the afternoon to collect Prince George, four, and Princess Charlotte, two.

The two young royals were walked into the hospital by their father to meet their new sibling, with Princess Charlotte thrilling the hundreds of assembled reporters and photographers with a little wave.

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Hopes that the family of five would pose together on the hospital steps were dashed, however, when Kensington Palace said on Twitter the children had been taken home shortly after their visit.

But the Duke of Cambridge emerged a few minutes later with his wife and new son.

Kate, 36, appeared to be in good health, wearing a bright red Jenny Packham dress with a white lace collar.

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The royal infant snuggled in a white lace shawl with a matching hat, was seemingly undisturbed by the commotion around him.

At one point, Kate was seen to give him a gentle pat on the back.

After smiling and waving at the crowds, the three left, with William telling reporters they were "very happy" and "delighted".

He added: "We didn't keep you waiting too long this time."

Holding up three fingers, he joked that he now had "thrice the worry" and, when asked about the new baby's name, he replied: "You'll find out soon enough."

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Kensington Palace has said there will be no extra childcare for the new baby, with William to spend a few weeks at home dedicated to helping his wife.

"Their Royal Highnesses would like to thank all staff at the hospital for the care and treatment they have received," the palace said.

"They would also like to thank everyone for their warm wishes."

The Queen, Duke of Edinburgh, William's father the Prince of Wales and his stepmother the Duchess of Cornwall, and his brother Prince Harry were "delighted" with the news, the palace added.

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