Duke of Cornwall () is a title in the Peerage of England, traditionally held by the eldest son of the reigning British monarch, previously the English monarch. The Duchy of Cornwall was the first duchy created in England and was established in a royal charter in 1337 by King Edward III. In 2022, Prince William became Duke of Cornwall with the accession to the throne of his father, King Charles III; William's wife, Catherine, became Duchess of Cornwall.
Legend
Some folk histories of the British Isles, such as Geoffrey of Monmouth's History of the Kings of Britain (1136), claim that the first leader of Cornwall was Corineus, a Trojan warrior and ally of Brutus of Troy, portrayed as the original settler of the British Isles. From then through the Arthurian period, such legendary dukes of Cornwall stood apart from the high king of Britain, while serving as his closest ally and, at times, as his protector (all per Monmouth's collected yarns). Notably in this tale, Gorlois, duke of Cornwall under King Uther Pendragon, rebelled when the king became obsessed with Gorlois' wife Igraine. Uther killed Gorlois and took Igraine: the son was King Arthur.
History
The historical record suggests that, following the Anglo-Saxon settlement of Britain, Cornwall formed part of a separate Kingdom of Dumnonia, which included Devon, although there is evidence that it may have had its own rulers at times. The Celtic southwest of Britain was gradually conquered by the emerging Germanic Kingdom of England, and after the Norman Conquest in 1066, the new rulers of England appointed their own men as earl of Cornwall, the first of whom was in fact a Breton of Cornouaille in Brittany.
Edward of Woodstock (widely known as 'The Black Prince'), the eldest son of Edward III, was made the first duke of Cornwall in 1337, after Edward III claimed the title of King of France. Cornwall was the first dukedom conferred within the Kingdom of England.
When the estate is without a duke, the possessor is the monarch, even if the former duke left surviving descendants. However, from the (minority) Jacobite perspective, on his father's death in 1701 the duchy was merged with the Crown.
Rights of the duke
The duchy includes over 220 square miles (570 square kilometres) of land, more than half of which lies in Devon. The duke has the right to the estates of all those who die without named heirs (bona vacantia) in Cornwall, and also appoints the High Sheriff of Cornwall; in most of England and Wales the Crown has these rights, the other exception being the Duchy of Lancaster, a private estate held in trust for the sovereign. The duke having these rights has contributed to the debate over the constitutional status of Cornwall.
In 2013, the duchy had a revenue surplus of £19 million, a sum that was exempt from income tax, though Prince Charles, the duke, chose to pay the tax voluntarily. Until 2011, if there was no Duke of Cornwall the income of the duchy went to the Crown. Under the Sovereign Grant Act 2011, revenues of the duchy now pass to the heir to the throne regardless of whether or not they are Duke of Cornwall. When the heir is a minor, 10% of revenues pass to them, with the balance passing to the Crown; the Sovereign Grant is reduced by the same amount.
Arms
thumb|Silver-plated cast copper alloy button with incised coat of arms of the Duke of Cornwall ()
The coat of arms of the duke of Cornwall is blazoned as sable, fifteen bezants, that is, a black field bearing fifteen golden discs. The arms are now used as a badge by the prince of Wales, and they appear below the shield in his coat of arms, along with his other badges.
The arms were adopted late in the 15th century, based on the arms of Richard, Earl of Cornwall. The bezants in Richard's arms were intended to represent peas, known in French as pois, as a punning reference to the French region of Poitou, of which he was count.
On 21 June 1968 a royal warrant augmented the aforementioned arms with the heir apparent's coronet, which consists of four crosses patée and four fleurs-de-lises with one arch (used only by the prince of Wales). The supporters are two Cornish choughs, each supporting an ostrich feather. The motto used with the arms is , meaning "high-spirited" in Middle Low German, the personal motto of the Black Prince.