King Charles Grants "His Highness" Title to Prince Rahim Al-Hussaini Aga Khan King Charles III has officially granted the title "His Highness" to Prince Rahim Al-Hussaini Aga Khan, marking his accession as the 50th hereditary Imam of the Shia Ismaili Muslim community. This follows the passing of his father, Prince Karim Al-Hussaini Aga Khan IV, who led the community for over six decades. The British monarchy granted the "His Highness" title to the Aga Khan dates back to 1957, when Queen Elizabeth II bestowed it upon Aga Khan IV upon his succession.