Perhaps the most remarkable fact about the fifth earl of Northumberland is that he successfully imposed his will on King Henry VIII, an achievement which can be put to the credit of very few. For although most of the life of this great lord was spent in disfavour, and in exclusion from the great offices (particularly the northern lieutenancies and Border wardenries) which had been held by his ancestors, he was nevertheless able to create conditions which eventually compelled the crown (but only after his own death) to confer these same offices on his heir, and so restore the traditional Percy ascendancy in the north. The earl therefore succeeded in reversing the political eclipse which had overshadowed his family in his own lifetime, and seemed to have ensured its future. The following pages attempt to explain how he did so, and also seek to throw light on the tactics by which the Tudors sought to undermine the influence of subjects thought to be “overmighty”, as well as the defensive reactions to which these gave rise on the latter's part. In this way it is hoped to clothe with flesh and blood some aspects of the successful struggle of the Tudor crown with those “rival powers” and “overmighty subjects” which established historical convention has seen as a prime Tudor contribution to the emergence of a more modern state.