Duchy of Cornwall from Duchy income, assisted by Grants-in-aid from the Queen. If there is no duke (for example, if the monarch does not have any male children) the duchy income reverts to the monarch and the annual Sovereign Grant is reduced annually by the amount of the duchy's income. The duchy was established on 17 March 1337 by the Royal Great Charter out of the former Earldom of Cornwall by Edward III for his son, Edward, Prince of Wales, the "Black Prince", who became the first Duke of Cornwall. The charter established that the Duke of Cornwall is to be the eldest
Edward the Black Prince at La Hogue received knighthood from his father. Then he "made a right good beginning", for he rode through the Cotentin, burning and ravaging as he went, and distinguished himself at the taking of Caen and in the engagement with the force under Sir Godemar du Faÿ, which endeavoured to prevent the English army from crossing the Somme by the ford of Blanquetaque. Early on Saturday, 26 August, before the start of the battle of Crécy, Edward, Prince of Wales received the sacrament with his father at Crécy, and took the command of the right, or van, of the army