Duke of Clarence was a substantive title created three times in the Peerage of England. The title Duke of Clarence and St Andrews has also been created in the Peerage of Great Britain, and Duke of Cla
William IV was styled "HRH The Duke of Clarence" between his creation in 1789 and his accession in 1830
Thomas of Lancaster, Duke of Clarence was a medieval English prince and soldier, the second son of Henry IV of England, brother of Henry V, and heir to the throne in the event of his brother's death.