Norfolk, John Mowbray, 3rd duke of (1415–61). After coming of age in 1436, Norfolk had a brief career in public service, in the relief of Calais from siege, as warden of the east march, and as an ambassador in Anglo-French negotiations. He allowed himself, however, to be implicated in the lawless activities of his steward Sir Robert Wingfield, which led to their detention in the Tower of London in 1440. Norfolk next quarrelled with Wingfield, assaulting his house with cannon, and consequently returned to the Tower in 1448. His ambition to dominate the shire of Norfolk was frustrated by the more potent ‘good lordship’ of William de la Pole, duke of Suffolk. After Suffolk's fall, Norfolk expected to have a free hand. He joined forces with Richard of York in demonstrations against the new court clique in 1450. It compelled him, however, to dismiss his own councillors who favoured York, a purge which occasioned the anarchy reported in the Paston letters for 1453, after which Norfolk again veered towards York in a half-hearted way. The first battle of St Albans had been fought before his arrival. He agreed to York's attainder in 1459, but joined him after the battle of Northampton. He escaped to London from the Yorkist defeat at St Albans in 1461, was in the junta which recognized Edward IV as king, and fought in his victory at Towton. His last military exploit was the seizure of Caister castle from John Paston. Norfolk's foremost interest remained his own regional aggrandizement; he was unreliable as both political ally and noble patron.

R. L. Storey