King Charles is overjoyed as Princess Beatrice expects new baby

King Charles has excitedly announced a new royal baby will be joining the family early next year.

King Charles has announced the royal ranks will be growing with his beloved niece Princess Beatrice due to give birth next year.

The palace revealed the joyful news early Wednesday morning (AEST) with a post on social media.

Princess Beatrice is set to become a mother once again. Picture: WireImage.

“Her Royal Highness Princess Beatrice and Mr Edoardo Mapelli Mozzi are very pleased to announce that they are expecting their second child together early in the new year; a sibling for Wolfie and Sienna,” the post read.

“His Majesty The King has been informed and both families are delighted with the news.”

Beatrice, 36, and her husband, 40, share a three-year-old daughter Sienna, who she has guarded from public view since her birth.

The princess is also a stepmother to eight-year-old Wolfie.

While young Wolfie is not in the line of succession, it is understood Beatrice has embraced him the same as if he were her own biological child.

Britain's Princess Beatrice of York and her husband Edoardo Mapelli Mozzi are delighted by the news. Picture: AFP.

Royal watchers were thrilled to be treated to a rare photo of Sienna and Wolfie shared by the palace.

It shows little Sienna with a darling mop of blonde hair held back with a red bow, walking hand-in-hand with her father and brother as they take a nature walk.

Known as a doting grandfather with a soft spot for Princess Beatrice, the daughter of his exiled brother Prince Andrew, the King’s spirits are evidently high following a tough year for the family.

Seen here with Princess Charlotte, the king is known to love welcoming babies to the family. Picture: BBC

Both the king and his daughter-in-law Princess Catherine had difficult cancer battles from which they are still recovering.

The new baby will be 11th in line to the throne, knocking aunty Princess Eugenie down one spot.

Like their sibling, the new baby will not carry a His or Hers Royal Highness title, nor will they be a prince or princess.

Prince Andrew, Duke of York, and Sarah, Duchess of York, leave Portland Hospital, London, with their newborn daughter Princess Beatrice in 1988. Picture: Getty Images.

The little one will be a cousin to Eugenie’s sons August and Ernest Brooksbank who she shares with her husband Jack Brooksbank.

They will also be a grandchild to Prince Andrew and Duchess of York Sarah “Fergie” Ferguson and a great niece or nephew to the king.