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 Thomas Holland: Edward had several natural sons before his marriage. With Edith de Willesford (died after 1385): With unknown mothers: Edward is often referred to as the "Black Prince". The first known source to use the sobriquet "Black Prince" was the antiquary John Leland in the 1530s or early 1540s (about 165 years after the death of the Black Prince). Leland mentions the sobriquet in two manuscript notes in the 1530s or early 1540s, with the implication that it was by that date in relatively widespread use. In one place, Leland refers in Latin to ""Edwardi Principis cog: Nigri"" (i.e.,