As keeper of the seal, and subsequently as chancellor, Neville was noted for his impartiality, and he oversaw a number of changes in the way the chancery operated.
Neville was deprived of the Great Seal in 1238 after quarrelling with King Henry III, but continued to hold the title of chancellor until his death.
[7] Neville's activities during the years immediately after 1207 are unknown, owing to the lack of royal records, but in December 1213 he was given custody of the Great Seal of the kingdom.
[8] Neville was appointed to the royal chancery in about 1214, largely through the patronage of Peter des Roches, the Bishop of Winchester and one of the king's favourites.
[14] Neville was also vice-chancellor of England under the chancellorship of Richard Marsh, who had been elected as Bishop of Durham in 1217 and spent most of his time attending to ecclesiastical affairs in his northern diocese.
In fact, if not in name, Neville was responsible for all the duties of the chancellorship, and he exercised most of the power of that office,[2][15] although Marsh continued to hold the title of chancellor until his death in 1226.
The council resulted in royal government coming under the control of Hubert de Burgh the Justiciar, Pandulf, and Peter des Roches, the Bishop of Winchester.
But it did not finally end until December 1223, and even then, as the king had not yet been officially declared of age, the ban on grants without a fixed time limit remained in force.
[12] The appointment was made by the great council during the minority of King Henry III, and Neville obtained a grant of the office for life.
[22] Unlike Hubert de Burgh, who lost his offices when Henry III attained his majority and took control of the government,[c] Neville remained chancellor with only slight disagreements until 1238,[15] although a confirmation of the lifetime nature of his tenure was made in 1232.
[2] Neville received a number of gifts and privileges from the king while chancellor, including the right of exemption from the seizure of his possessions by any royal or other secular official.
[28] Neville was elected Archbishop of Canterbury on about 24 September 1231 by the monks of Canterbury, but his election was quashed in early 1232 by Pope Gregory IX,[2][29] on the grounds that Neville was an illiteratus or illiterate, even though he had been found to be literatus in 1214 when appointed dean; literatus in this sense meant "learned" rather than "literate".
In 1230 he was regent of England while Henry was absent in France,[2] during which time he met with Llywelyn the Great in an unsuccessful attempt to negotiate an agreement that would resolve the disputes between the English and the Welsh.
[2] Neville died between 1 and 4 February 1244[19] at the palace he had built in London in what was then New Street, subsequently renamed Chancery Lane because of his being Lord Chancellor.
[2] After Neville's death Matthew Paris described him as "a man laudable in all things, and a pillar of fidelity in the business of the kingdom and the king".