Princess Beatrice has given birth to her second child, named Athena, Buckingham Palace has announced.
Beatrice and her husband Edoardo Mapelli Mozzi welcomed their second child a week ago on 22 January at the Chelsea and Westminster Hospital in London, said the palace statement.
Athena was born several weeks prematurely and weighed 4lb 5oz, but is said to be healthy and doing well.
The King and Queen were said to be delighted at the baby's safe arrival.
Beatrice and her daughter are both doing well, says the palace, and the family are spending time with Athena's older siblings Wolfie and Sienna.
The parents thanked staff at the London hospital for their "wonderful care".
Beatrice had been due to give birth in early spring and in December had received medical advice not to travel long distances.
The new baby, Athena, is the grandchild of the Duke and Duchess of York and a great-niece to King Charles.
In ancient Greece, Athena was the goddess of war, handicraft and wisdom.