After an undoubtedly tiring 11-hour labour, the future King's mother and father are said to have ordered two pizzas to the Lindo Wing of St Mary's Hospital, Paddington at around 8:45pm.
While the Duke and Duchess of Cambridge tucked into their pizzas, the news broke via email press release that their baby son had been born at 4:24pm that afternoon weighing 8lb 6oz.
Pizza is one of Prince William's childhood favourites. He and Prince Harry once forged a note asking the Kensington Palace chef Darren McGrady to "cancel the chicken and broccoli and cabbage tonight and give the boys pizza please.” The plot was instantly foiled when Darren recognised a seven-year-old's scrawly handwriting.
The royal couple and their infant son spent the night in the Lindo Wing while celebrations kicked off all over the world.
In a brief statement released on the day of the birth of his first child, Prince William said that he and his wife "could not be happier."
Meanwhile, first-time grandfather Prince Charles is said to have celebrated the birth with a glass of champagne while on his visit to Yorkshire with Camilla, Duchess of Cornwall. He released a statement that said he was "enormously proud and happy" about the birth of his grandson.
William, Kate and their newborn son are expected to leave the hospital on Tuesday.
Photographers, reporters, cameramen and well-wishers remain camped outside, poised to get the first photo of the new family.
It is understood that RAF Search and Rescue helicopter pilot William, 31, will now enjoy two weeks paternity leave, as allowed by the Ministry of Defence.
Kate, 31, will take maternity leave, although it is not known how much time she will take off.
It remains to be seen whether the pair will return to Kate's parents' house in Bucklebury, Berkshire, while they get to know their baby. Rumours have suggested that Kate will spend the first six weeks of motherhood at the rural family home before returning to Kensington Palace.