No. It was usurped by the English crown. Scotland escaped that fate, at least until a bit later.Probably by the same.
We can keep playing that game until we get to the first migration of man if you like?
http://duchyofcornwall.eu/history02.phpHence the emerging requirement to ensure that the duchy was placed firmly within England, the downgrading of the charters and the growth of duchy ‘rotten boroughs’. These gerrymandered parliamentary seats were created to maintain ducal powers and privileges through the exercise of parliamentary leverage - which in turn gave rise to early attempts at what was to later become an avalanche of so-called ‘Duchy of Cornwall Management Acts’. Acts that were themselves designed to lessen the duke’s reliance on troublesome, and constitutionally ‘dangerous’, duchy charters and oversee the beginnings of the slow transformation from Duchy of Cornwall constitutional entity to pseudo-‘private estate’.

