The feud between Somerset and York was because York felt dishonoured by Somerset’s easy surrender of Rouen and other lands of York’s appanage in 1450. As the son of Richard, Earl of Cambridge; who was executed for treason against Henry V, York was sensitive to the issue of family honour. He presented an article to the king in 1452, criticising Somerset for his failure to defend Rouen from attack and his surrender of Rouen in 1449 despite soldiers protesting. Despite Somerset being lieutenant-general in Normandy since 1445, York was still captain of Rouen and it was his responsibility to govern his appanage. The surrender of Rouen was a treasonable offence and York was dishonoured because of this, despite not being there in person to defend. York demanded Somerset be tried for the treasonable surrender of Rouen and other towns in order to clear his name. York’s bitter feud with Somerset was centred on the loss of English territories in France and said that this was his main reason for opposing Henry.
York’s opposition of the king at Dartford in 1452 and at St.Albans in 1455 were very risky. These treasonable offences had to be motivated by more than a quarrel with Somerset. York mainly took arms against the king because of the position he had been put in by the suspicions of Henry and Margaret about his character. As the son of a traitor, York felt that Henry had a grudge against him. Suspicions that York was plotting treason were raised when his armourer was hanged after he suggested that York was the rightful king. These suspicions were worsened by Cade rebels demanding for York to be the king’s chief councillor and Cade claiming that he was a Mortimer. Because of these suspicions, York returned early from Ireland in 1450 to clear his name. He also made his first bill of complaint to Henry, outlining his fear of attainder, his position as heir apparent and unpaid debts. When Henry imprisoned Thomas Young in 1451 for proposing that York was heir apparent York's fears of possible attainder grew and so did his sense of isolation from the court faction. It was York's need to assure his security and address his urgent financial situation, along with his hatred of Somerset which caused him to oppose the king in battle in 1452. In taking arms against the king, York was lucky to escape execution for treason after he was arrested because it confirmed the suspicions the king had of York.
In his second bill of complaint in 1450, York echoed the fears of the nation; the breakdown of law and order, the loss of Normandy and high taxes. These concerns may have been held by York himself, but he used the bills in order to try and win public support which he wouldn’t have received by talking about his personal concerns. York posed as a figure of reform against the failures and misrule of the court faction which provided further charges for him to lay against Somerset. Parliament expressed their discontent at the loss of land in France, the precarious state of law and order and the poverty of the crown but even this was not enough to treasonously oppose the king. Only the Nevilles and the Earl of Devon supported York against Somerset and the Percys rather than against the king. And it wasn’t until after Henry transferred his lands in Wales to Somerset in 1453 that Warwick sided with York.