The Prince of Wales inherited the titles held by his father, Prince Philip, following his death on Friday.
Upon Prince Philip’s death, Charles immediately became the Duke of Edinburgh, Earl of Merioneth, and Baron Greenwich.
The inheritance of these titles automatically passed on to Prince Charles as the eldest son of the Queen and Prince Philip.
The Dukedom of Edinburgh is now a subsidiary title and will be rarely used in reference to the Prince of Wales.
Upon the death of Queen Elizabeth II, Prince Edward will become the Duke of Edinburgh, and the Countess of Wessex shall become the Duchess of Edinburgh.
This will not happen until the title reverts back to the Crown upon the death of the monarch, leaving the new King Charles to create the Dukedom again for his younger brother.
Named after the capital city of Scotland, the Dukedom of Edinburgh was first created on 15 July 1726 during the reign of King George I, who bestowed it upon his grandson, Prince Frederick (1707-1751), who became Prince of Wales three years later.
Prince Frederick predeceased his father in 1751 and his titles passed to his eldest son. The future King George III was thus briefly known as the Duke of Edinburgh until he was created Prince of Wales.
When Prince George succeeded as George III upon his grandfather’s death in 1760, the title merged with the Crown.
The second creation of the title of just Duke of Edinburgh (without Gloucester) goes back to the reign of Queen Victoria; on 24 May 1866, Prince Alfred (1844-1900) was given the titles of Duke of Edinburgh, Earl of Ulster and Earl of Kent
The third creation of the title occurred during the reign of King George VI, on 20 November 1947. It was bestowed upon Philip Mountbatten.