The UK's Princess Eugenie, granddaughter of Queen Elizabeth II and the Duke of Edinburgh, gave birth to a boy on Tuesday.
Her husband, Jack Brooksbank, was present at the birth, and the royal family said the princess and her 3.6-kilogram baby were doing well.
The royal family confirmed the birth on Twitter and Eugenie released a black-and-white image on Instagram.
The baby's name has not yet been made public. He was born at London's Portland Hospital.
The boy is Eugenie and Mr Brooksbank’s first child – and a first grandchild for the Duke of York and Sarah, Duchess of York.
The baby is the ninth great-grandchild of Queen Elizabeth and the Duke of Edinburgh and 11th in line to the throne.
The couple married at St George's Chapel at Windsor Castle in October 2018
Eugenie also announced her pregnancy on Instagram with a photo of a pair of baby slippers.
The birth is a welcome bit of good news for the monarch after a couple of days to forget.
On Sunday it was revealed that in 1979 she had lobbied the UK government to amend a draft law to conceal the full extent of her wealth.
On Monday, she was criticised for driving up the price of renewables by using an auction system to lease parts of the crown-owned UK seabed for wind farm licences.