His Majesty created his eldest son, Edward, The Black Prince, in 1337 (then Earl of Chester), Duke of Cornwall, and subsequently Prince of Wales, when the Dukedom merged in the Principality, and has ever since been vested in the heir apparent to the Crown, who, at his birth, becomes Duke of Cornwall.The second dukedom was conferred in 1351, upon Henry of Grosmont (son and heir of the Earl of Derby), under the title of Duke of Lancaster, which dignity expired at His Grace's decease, in 1360, without male issue; but was re-conferred, in 1362, upon John of Gaunt,
who had espoused the Duke's second daughter, and eventually sole heiress, Blanche of Lancaster. In the reign of ELIZABETH I, in 1572, the whole order became utterly extinct; but it was revived about fifty years afterwards by her successor, in the person of George Villiers, 1st Duke of Buckingham.A duke is styled "His Grace" and the "Most Noble", and he is officially addressed by the Crown, "Our right trusty and right entirely beloved Cousin and Counsellor".
The most recent non-royal dukedom to be conferred was in 1900 for Alexander [Duff], 6th Earl Fife, KG, KT, etc, who was created Duke of Fife (2nd creation).
THE ROBES worn by a duke at a coronation consist of a mantle and surcoat of common velvet, lined with white taffeta, the mantle doubled from the neck to the elbow with ermine, having four rows of spots on each shoulder.
His Grace's parliamentary robes are of fine scarlet cloth, lined with taffeta, having four guards of ermine on the right side, and three on the left, placed at equal distances, each guard surmounted with gold lace; the robe is tied up to the left shoulder by a white ribbon.
His cap is of crimson velvet, lined with ermine, having a gold tassel at top; and his coronet, which is of gold, is set with strawberry leaves, also of gold.