In November 1470 Parliament attainted Edward IV and Richard, Duke of Gloucester.
November 1470 saw Parliament under the control of the Earl of Warwick. This followed Warwick’s pact with Margaret of Anjou, known as the Angers Agreement, carefully orchestrated uprisings in the north and the Duke of Clarence and Earl of Warwick’s return to England.
Edward, facing overwhelming odds, had little choice but to evade being captured. He chose to go to the safety of his sister’s court in Burgundy. Following the flight into exile of the King and Duke of Gloucester, the Earl of Warwick sought to consolidate his position.
With King Henry VI’s readeptation in mind, crown properties needed to be taken from the outgoing regime and passed to the returning Lancastrian Monarch. Furthermore, the rights of Edward and his children to the crown needed to be removed. The legal mechanism through which this could be achieved was an Act of Attainder which in effect outlaws the person named and directs the reallocation of his or her titles and possessions. The parliamentary roll containing the wording of the attainder has been lost. We do know that Edward IV and Richard Duke of Gloucester were both attainted, though, most likely being cited as traitors to King Henry VI‘s rightful rule.
An Act of Attainder typically strips somebody of their lands, income, titles, rank, rights to inherit and rights to legal recourse. Some attainders extended to the attained person’s line, thus removing any possibility of an heir making a claim in years to come. In Edward and Richard’s case, it is almost certain that the full range of measures would have been applied. It was a punitive measure designed to remove all influence that the pair had on English soil. An Act of Attainder against an anointed king would be one of the first items of business in a Parliament, and so 26 November 1470 is assumed to be the date upon which the Act was passed.