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 burnt, and that 3,000 persons of all ranks and ages were massacred. However modern scholarship, including the historian Richard Barber writing in 2008 in the "Oxford Dictionary of National Biography", and drawing on a wider range of evidence, places casualties much lower than Froissart did—around 300 garrison soldiers and civilians in total. The prince returned to Cognac; his sickness increased, and he was forced to give up all hope of being able to direct any further operations and to proceed first to Angoulème and then to Bordeaux. The death of his eldest son Edward, which happened at this time, grieved