The Queen has given the title of the Duke of Cambridge to Prince William, his wife Kate Middleton will be Her Royal Highness the Duchess of Cambridge. Media speculates, that this title was chosen because the last Duke of Cambridge also married a commoner for love. Prince William will be the 3rd Duke of Cambridge.
Prince George, known as the 2nd Duke of Cambridge, was born in 1819. He was a grandson of George III and the only son of Prince Adolphus Frederick, the 1st Duke of Cambridge.
Should you meet them it you are supposed to adress them as “His Royal Highness The Duke of Cambridge” and “Her Royal Highness The Duchess of Cambridge.”
William has also become the Earl of Strathearn and Baron Carrickfergus, which means Miss Middleton will also become the Countess of Strathearn and Baroness Carrickfergus.
Williams Parents Charles and Diana were made Prince and Princess of Wales before their wedding. Prince Charles second Wife has the title Dutchess of Cornwall.