[1] Despite a record of conflict with other members of the nobility, he enjoyed the confidence of the King, who appointed him Lord Deputy of Ireland, an office in which he was a notable failure.
[1] He was one of the principal magnates in Derbyshire and Nottinghamshire, and like many nobles of the time, he was prepared to assert his power by force, and even to act in open defiance of the law.
The King appointed a particularly strong commission of oyer and terminer headed by his brother George, Duke of Clarence, to restore order in the region.
The commission does not seem to have reached a verdict, and the following year Grey and the Vernons were made to swear oaths not to intimidate the jurors appointed to investigate the matter.
Like most medieval English kings, Edward IV was normally prepared to leave Ireland to be governed by the Anglo-Irish nobility, but he made intermittent efforts to assert his authority over that Kingdom.
In 1478, concerned at the increasing power of Gerald FitzGerald, 8th Earl of Kildare and his family, he dismissed him as Lord Deputy and appointed Grey in his place.
After Grey's death, Katherine, who received substantial lands under his will, quickly remarried Edward IV's nephew William de la Pole.
He is said to have been keenly interested in alchemy, and obtained a licence from the King for the transmutation of metals, on condition that he must inform the Crown if he succeeded in producing gold.