ITV News' Business Editor, Laura Kuenssberg, looks at how the royal baby could provide a much needed boost to the economy.
The royal baby appeared to wave as he was introduced to the crowds outside the hospital for the first time.
The Duke and Duchess of Cambridge proudly showed the world their baby son, a future king, before taking him home tonight.
The UK economy is expected to notch up an improved quarter of growth when official figures are published later, adding to hopes of a sustained recovery.
A widely-expected rise of around 0.6% in gross domestic product (GDP) would double the previous increase of 0.3%, building on national cheer fuelled by the birth of the royal baby and the summer heatwave.
The Duke and Duchess of Cambridge have taken their new born son to stay with Kate's parents in the Berkshire village of Bucklebury.
William is on two weeks paternity leave and it is expected the couple will enjoy the family support of Michael and Carole Middleton as they adjust to their new role as mum and dad.
A Kensington Palace spokesman said:
"This is now private and quiet time for them to get to know their son.''
The Duke and Duchess of Cambridge and their son have arrived at the Middleton family home in Bucklebury.
Timmy Mallett returned to Windsor today to add the latest edition to the royal family to a portrait of the Duchess of Cambridge.
Timmy decorated a phonebox with paintings of the Queen, the Duchess of Cambridge and Prince Harry last year.
Today he added a crown, a pram and a blue ribbon on the Duchess of Cambridge's portrait, displayed on the side of the 'Ring-a-Royal-Phonebox'.
Around half an hour after the visit from the Queen, William, Kate and their baby were seen being driven away from Kensington Palace.
The Duchess was sitting in the back of the vehicle next to the baby seat while the Duke was a front-seat passenger.
As he was introduced to the world, the Duke and Duchess of Cambridge's son was wrapped in a white shawl from GH Hurt and Son Ltd.
The company has a long-standing connection with the royal family. Other members of the royal family have been presented with these shawls in the past and the Duke of Cambridge had a similar shawl when he was a baby.
Prince Harry has visited the Duke and Duchess of Cambridge and seen their new baby, Kensington Palace has said.
The Duke and Duchess of Cambridge have left Kensington Palace with their newborn son. It is unclear at this stage where the royal couple and the prince are travelling to.
Dressed in a turquoise floral outfit, the Queen looked relaxed as she left Kensington Palace after spending just over half an hour with the Duke and Duchess of Cambridge's first child.
She had travelled to see William and Kate and their baby without the Duke of Edinburgh who is still convalescing at Windsor Castle following exploratory abdominal surgery last month.