I know the twins make you nervous, but they are my nephews.
The title was made; heritable in order of primogeniture, and in the case of archbishops through their nephews.
In the general anarchy Charles succeeded in escaping, defeated the Neustrians at Ambleve, south of Liege, in 716, and at Vincy, near Cambrai, in 717, and forced them to come to terms. In Austrasia he wrested the power from Plectrude, and took the title of mayor of the palace, thus prejudicing the interests of his nephews.
William had two surviving brothers, beside several nephews.
As a matter of fact Lancaster was a more honest man than his enemies suspected; he hastened to acknowledge his little nephews rights, acknowledged him as prince of Wales, and introduced him as his grandfathers heir before the parliament of January 1377.