With the death of Prince Philip, the Duke of Edinburgh, on 9 April 2021, his titles passed to his eldest son and heir, Prince Charles, The Prince of Wales. Prince Charles has gained the titles Duke of Edinburgh with its subsidiary titles of Earl of Merioneth and Baron Greenwich, of Greenwich in the County of London.
The College of Arms confirmed, “These peerages are hereditary and on the death of His Royal Highness have passed to his eldest son, HRH The Prince of Wales. In the event of the Prince of Wales or any subsequent holder of these titles succeeding to the Crown, these titles and all others held will merge with the Crown.”1
However, you may remember that it was announced upon the marriage of his younger son Prince Edward to Sophie Rhys-Jones that “The Queen, The Duke of Edinburgh and The Prince of Wales have also agreed that The Prince Edward should be given the Dukedom of Edinburgh in due course, when the present title now held by Prince Philip eventually reverts to the Crown.”2
Upon the death of Queen Elizabeth II on 8 September 2022, Prince Charles automatically became King, and his titles merged with the Crown, including the title of Duke of Edinburgh. This meant that Charles was now free to recreate the title for his brother Prince Edward, which he did, for life, on 10 March 2023.