The Queen has expressed her delight at the birth of her ninth great-grandchild as Princess Eugenie and Jack Brooksbank welcomed their first child, a boy, overnight.

Buckingham Palace released the following statement on behalf of the Queen herself.

"The Queen, The Duke of Edinburgh, The Duke of York, Sarah, Duchess of York, and Mr and Mrs George Brooksbank have been informed and are delighted with the news," it reads.

"This is Princess Eugenie and Jack Brooksbank's first child, The Duke of York and Sarah, Duchess of York's first grandchild, and the ninth great-grandchild for The Queen and The Duke of Edinburgh. Her Royal Highness and her child are both doing well."

Princess Eugenie made the announcement with a sweet post on her Instagram.

Princess Eugenie's parents, Prince Andrew, the Duke of York and Sarah Ferguson, the Duchess of York are yet to publicly comment about the arrival of their first grandchild, but Ferguson liked the official announcement on social media.

The Duke and Duchess of Sussex are understood to have privately congratulated the couple, but the Duke and Duchess of Cambridge and Princess Beatrice are yet to comment publicly on the birth.

There is no word yet as to what the baby will be named, as the royal family typically wait two days before publicly sharing a baby's name to the media.