Kate Middleton is now the Colonel of the Irish Guards.
The title was previously given to Prince William. Now that Kate has her honourary title, her husband has assumed the role of Colonel of the Welsh Guards.
Meanwhile, Queen Consort Camilla has been made Colonel of the Grenadier Guards.
This comes after Kate Middleton and Prince William joined Queen Consort for a Christmas event.
"Thank you to everyone who has helped make #TogetherAtChristmas so special," the Prince and Princess of Wales said in a social media statement following the event.
"It was fantastic to celebrate inspiring individuals and outstanding organisations with you all."