Duke and Duchess of Cambridge
Prince William and Kate Middleton were bestowed the title by Queen Elizabeth II on their wedding day, April 29, 2011. The last person to hold the dukedom prior to William was Queen Victoria's cousin Prince George, 2nd Duke of Cambridge, who died in 1904.
Prince and Princess of Wales
William was appointed the title in September 2022 following the death of his grandmother Queen Elizabeth and accession of his father King Charles III. In the change-up, Kate became Princess of Wales, a title previously held by William's mother Princess Diana during her marriage to Charles—then known as Prince Charles—from 1981 to 1996.
Given that Kate (born Catherine Middleton) did not come from a British royal family, her formal name is actually Catherine, Princess of Wales.
Duke and Duchess of Cornwall
The couple also inherited this title upon King Charles' accession as the British monarch. The role was previously held by Charles and his wife Queen Camilla, who technically became the Princess of Wales when she married the royal in 2005 but opted to use her duchess title prior to becoming queen consort.
Duke and Duchess of Rothesay
In Scotland, William and Kate are also known as the Duke and Duchess of Rothesay, titles they inherited from King Charles and Queen Camilla when the line of succession shifted upon the death of Queen Elizabeth. Other Scottish titles they were bequeathed include Earl and Countess of Carrick, Baron and Baroness of Renfrew, and Lord and Lady of the Isles.
As the heir apparent, William additionally gained the title of Prince and Great Steward of Scotland when his dad became the new sovereign.
Earl and Countess of Strathearn
Queen Elizabeth bestowed the Scottish titles upon William and Kate on their wedding day. They couple were referred to as such before inheriting the title of Duke and Duchess of Rothesay in 2022.
Baron and Baroness Carrickfergus
In Northern Ireland, William and Kate are known as Baron and Baroness Carrickfergus, another title they received from Queen Elizabeth upon their marriage. Kate is also sometimes referred to as Lady Carrickfergus.
Earl and Countess of Chester
King Charles held the title of Earl of Chester from 1958 until his accession in 2022, when William inherited the role as the heir apparent. Through marriage, Kate took on the role of Countess of Chester.
Commodore-in-Chief of Scotland and Commodore-in-Chief of Submarines
In August 2006, William was appointed Commodore-in-Chief of Scotland and Commodore-in-Chief of Submarines by Queen Elizabeth "in recognition of the strong links between the Royal Navy and the Royal Family," according to the royal family website.
Colonel of the Irish Guards and Colonel of the Welsh Guards
In December 2022, Kate was appointed the Colonel of the Irish Guards, a role previously held by her husband. Meanwhile, William inherited the title of Colonel of the Welsh Guards from his dad King Charles.
Colonel-in-Chief, 1st The Queen's Dragoon Guards; Commodore-in-Chief, Fleet Air Arm; Royal Honorary Air Commodore, RAF Coningsby
Kate was named Commodore-in-Chief of the Fleet Air Arm, Colonel-in-Chief of the 1st Queen's Dragoon Guards and Royal Honorary Air Commodore, RAF Coningsby by King Charles in August 2023.
The title of Colonel-in-Chief of the 1st Queen's Dragoon Guards was one previously held by Queen Elizabeth The Queen Mother from 1959 to 2002 and Charles from 2003 to 2023.
Kate landed her first senior role for the Royal Air Force (RAF) in becoming the a Royal Honorary Air Commodore for RAF Coningsby. The title is also a sweet nod to her grandfather Captain Peter Middleton, who flew alongside Queen Elizabeth's late husband Prince Philip during a two-month aerial tour of South America in 1962.
Colonel-in-Chief, Mercian Regiment; Colonel-in-Chief, Army Air Corps; Royal Honorary Air Commodore, RAF Valley
William was given the titles of Colonel-in-Chief of The Mercian Regiment and Colonel-in-Chief of Army Air Corps in August 2023 by his dad, King Charles, after a reshuffling of military appointments. In addition, he was appointed as Royal Honorary Air Commodore, RAF Valley, where he previously spent three years as a search and rescue pilot.