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 "Edward the Prince, cognomen: The Black"); in the other, in English to "the Blake Prince". In both instances, Leland is summarising earlier works – respectively, the 14th-century "Eulogium Historiarum" and the late 15th-century chronicle attributed to John Warkworth – but in neither case does the name appear in his source texts. In print, Roger Ascham in his "Toxophilus" (1545) refers to "ye noble black prince Edward beside Poeters"; while Richard Grafton, in his "Chronicle at Large" (1569), uses the name on three occasions, saying that "some writers name him the black prince", and elsewhere that he was "commonly called the