Prince George and Princess Charlotte have been introduced to their new baby brother for the first time.

The youngsters were taken to the Lindo Wing at St Mary’s Hospital in Paddington, London, to meet the newborn Prince of Cambridge by their father the Duke of Cambridge.

The Duchess of Cambridge, who gave birth to the 8lb 7oz baby boy at 11.01am on patriotic St George’s Day, was believed to be waiting in her private suite for her eldest children.

William, who was at Kate’s side for the birth, left shortly after 4pm to collect four-year-old George and Charlotte, who turns three on May 2, from Kensington Palace.

George, who has spent the day at school and was dressed in his school uniform, appeared a little shy as he arrived, but Charlotte waved at the cameras twice, turning to do so and smiling as she walked up the steps.

Kensington Palace said the baby’s name would be “announced in due course”, but Arthur is already the favourite with punters, according to the bookies.

The new prince is fifth in line to the throne, and the Queen and the Duke of Edinburgh’s sixth great-grandchild.

The duchess was driven to the exclusive Lindo Wing before 6am on Monday in the early stages of labour, ready for the birth of their third child.

Kensington Palace announced the baby’s arrival in a statement shortly after 1pm and said the Queen, the royals and Kate’s family were thrilled at the news.

“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 palace said.

A formal notice of the birth was placed in the forecourt of Buckingham Palace on an ornate golden stand , and a celebratory over-sized Union Flag was raised from the roof of the Queen’s London home.

Senior footman Olivia Smith (left) and footman Heather McDonald place a notice on an easel in the forecourt of Buckingham Palace formally announce the birth of the baby boy (Stefan Rousseau/PA)
Senior footman Olivia Smith (left) and footman Heather McDonald place a notice on an easel in the forecourt of Buckingham Palace formally announce the birth of the baby boy (Stefan Rousseau/PA)

Prime Minister Theresa May led the messages of support for William and Kate, saying: “My warmest congratulations to the Duke and Duchess of Cambridge on the birth of their baby boy.

“I wish them great happiness for the future.”

The arrival of a baby boy was a surprise for the duke and duchess, who chose not to find out what they were having.

A huge media presence gathered outside the private Lindo Wing in anticipation of the birth, the same unit where George and Charlotte were born, as were William and Prince Harry.