Princess Eugenie and her husband, Jack Brooksbank, welcomed their third child, Adelaide Elizabeth Annina Brooksbank, on August 3, causing a significant shift in the royal line of succession. The new baby is now 15th in line to the throne, moving the Duke of Edinburgh down to 16th place.

Eugenie herself remains at number 12, positioned behind her older sister, Princess Beatrice, and Beatrice's two children, Sienna Mapelli Mozzi and Athena Mapelli Mozzi. Eugenie's two sons, August and Ernest, are 13th and 14th in line, respectively. Adelaide Brooksbank, as she does not possess a royal title, is styled as Miss Adelaide Brooksbank in the line of succession.

Adelaide's name carries historical significance. "Adelaide" pays homage to Queen Adelaide, the wife of King William IV, and to Maria Adelaide, a revered figure in Portugal. Her middle name, Elizabeth, honors her great-grandmother, the late Queen Elizabeth, a name frequently chosen for royal children, including Princess Beatrice. The name Annina is reportedly of personal importance to Eugenie and Jack.

Thanks to the Succession to the Crown Act of 2013, Adelaide will maintain her 15th position even if Eugenie has another son. This act ensures that female royals born after October 2011 are not displaced in the line of succession by younger male royals, effectively ending male preference primogeniture before Prince George, Prince William's son, was born in July 2013.

Ahead of Eugenie in the line of succession are Prince William, Prince George, Princess Charlotte, Prince Louis, Prince Harry, Prince Archie, Princess Lilibet, Andrew Mountbatten-Windsor, Princess Beatrice, Sienna Mapelli Mozzi, and Athena Mapelli Mozzi.

Despite his connection to the late Jeffrey Epstein, Andrew Mountbatten-Windsor has not been removed from the line of succession. While his brother, King Charles, stripped him of his princely title after the scandal, removing him from the line of succession entirely would necessitate an Act of Parliament and the King's consent. Andrew's daughters, Beatrice and Eugenie, kept their princess titles, but their children do not hold royal titles as they are not direct grandchildren of the reigning monarch.

Eugenie and Jack announced Adelaide's arrival on August 4, sharing a photo of their sleeping baby. Eugenie wrote on Instagram, "Jack and I are so excited to announce Baby Girl Brooksbank!! We are beyond in love with our girlie." The palace released a statement confirming, "Her Royal Highness Princess Eugenie and Mr Jack Brooksbank are delighted to announce the safe arrival of their daughter, born on Monday, 3rd August 2026, at 6:20 p.m., at a hospital in Lisbon, Portugal. The baby was born weighing six pounds nine ounces." The statement concluded by noting, "Their Majesties The King and Queen and other members of The Royal Family were delighted to be informed of the news."