Prince Harry and his fiancee Meghan Markle. Picture: AP

After months of speculation, the Royal Family has confirmed that Prince Harry and his soon-to-be wife, Meghan Markle, will be known as the Duke and Duchess of Sussex.

Kensington Palace made in the announcement on its official Twitter account on Saturday morning. The statement read: "The Queen has today been pleased to confer a Dukedom on Prince Henry of Wales. His titles will be Duke of Sussex, Earl of Dumbarton and Baron Kilkeel.

"Prince Harry thus becomes His Royal Highness The Duke of Sussex, and Ms. Meghan Markle on marriage will become Her Royal Highness The Duchess of Sussex. (sic)"

The Duke and Duchess of Sussex title has not been used since 1843.

There has only been one Duke of Sussex, the sixth son of George III, and his two marriages were not approved by the king so there has never been a Duchess and his children were considered illegitimate.

Harry and Meghan's wedding, however, received the official royal seal of approval from Queen Elizabeth II, so a repeat of history is unlikely.