Eugenie’s grandparents Queen Elizabeth II and Prince Philip and parents, Prince Andrew and Sarah, Duchess of York, are “delighted” by the news, the palace said.
“Her Royal Highness and her child are doing well,” the palace added.
Eugenie a photo on Instagram of herself and Brooksbank holding onto their baby boy’s hand. She captioned the post with three blue heart emojis.
Eugenie and Brooksbank married in October 2018 and announced in September that they were expecting their first child.
Eugenie revisited “happy memories” while celebrating her second wedding anniversary with Brooksbank in October.
“Been the best 2 years married to you and 10 years with you in total.. happy memories always my dear Jack,” she wrote on Instagram.
Eugenie is the younger sister of Princess Beatrice, who married Edoardo Mapelli Mozzi in July. She is the cousin of Prince William and Prince Harry.