Now, per a new Instagram post, the couple has revealed their baby's name: August Philip Hawke Brooksbank. The name is a tribute to Prince Philip, Eugenie's grandfather.
"Thank you for so many wonderful messages," Princess Eugenie wrote alongside the pictures of the new family. "Our hearts are full of love for this little human, words can't express. We are excited to be able to share these photos with you."
It's also believed that the couple selected the first name August based on Queen Victoria's consort Prince Albert, whose middle name was August.
August is the Queen and Prince Philip's ninth great-grandchild and was born at The Portland Hospital in London. Portland is the same hospital that Megan Markle had her son Archie at, as well as where Princess Eugenie herself was born in 1990.