Grygges’s background is obscure, but it seems quite likely that he was related to Roger Grygge, who had acted in 1403-4 as receiver of the estates in Norfolk and Suffolk belonging to Michael de la Pole, earl of Suffolk,
Although the evidence is lacking, we may assume that Grygges was already employed by de la Pole, perhaps as his receiver-general,
As receiver-general of the dowager’s estates in East Anglia, Grygges carried out many tasks on her behalf. For instance, in July 1451 he consulted with a carpenter from Norwich about building a mill on the de la Pole property at Cawston,
