After the battle of St Alban's Henry VI was escorted back to London, treated with due respect by York and his followers, and lodged in Bishop Kemp's house. After the Whitsuntide celebrations, during which Henry rather pointedly insisted that York, rather than the Archbishop of Canterbury, placed the crown on his head the King left for Windsor, apparently not under constraint.
Changes in government removed various offices from Somerset and bestowed them on Warwick and the Bourchiers. Notably Warwick became Captain of Calais, a role from which he was not easily to be displaced! York became Constable.
The Parliament of that summer exonerated York and his party for their part in the events of St Alban's by putting the blame on the dead Somerset. Other charges were largely dropped, with a general pardon issued at the end of the Parliament that was taken up by many persons, including the Duke of Exeter.
York at this stage was not formally Protector, but the King's rule was certainly somewhat nominal, and trouble flared between lawless elements in various parts of the country including London, Devon and Derbyshire. When Parliament met again in November the King was reported sick again, and the peers invited York to act as Lieutenant. It was provided that York should only be dismissed from the protectorate by the King with the assent of the lords spiritual and temporal, thus giving him rather more 'job security' than before.
York's first task was to restore order in Devon, the worst of the troublespots, and he performed this duty with some success. The Earl of Devon (York's supporter in 1452) and Lord Bonville his main rival were both placed in custody.
York's next significant project was less successful. It was a Bill of Resumption intended to take back many of the crown lands Henry had given away. (The intent being to improve the crown's hopeless financial position.) It provoked fierce opposition, especially among the peers, with Queen Margaret only one of many seeking exemption.
As mentioned, York's government was rather narrowly based, relying heavily on the Nevilles and Bourchiers and depending for its survival on at least the passive support of the majority of the peerage. There was not the necessary consensus to undertake the policy of resumption and the result was that York resigned (25 February 1456), even before the Parliament was ended. He went off to Sandal, and Warwick and Salisbury joined him in the north.