Despite the recently concluded peace between England and France, dissension is rife within the English court. Suffolk's influence, both at court and with the new Queen Margaret, intensifies.
The fractious English nobles unite in their common aim to get rid of the Duke of Gloucester. His wife Eleanor, the Duchess of Gloucester, aspires to the crown and is lured by a priest, John Hume, who is in the pay of Suffolk, to consult a witch about her ambitions. She is brought to trial and banished. Gloucester resigns his staff of office, allowing Henry to become king in his own right.
Somerset returns from France with the news of the loss of all English territories. York and others seize this opportunity to implicate Gloucester in the loss of France and to accuse him of treason. Suffolk, Margaret, Winchester and York agree that Gloucester should be murdered.
Meanwhile, there is a rebellion in Ireland and York is sent by Suffolk to deal with the crisis. York incites Jack Cade, a clothier posing as Mortimer, to promote further conflict by rebelling in Kent. Gloucester is murdered and the king turns against Suffolk, who is subsequently banished and murdered. Cardinal Beaufort (Winchester) outlives his old enemy by only a few hours.
Cade's rebellion is finally quashed but York returns to claim the crown, supported by his sons, Edward, Richard and George, and by Salisbury and Warwick. The two sides take up arms, Henry supported by Margaret, Somerset, Buckingham and the Cliffords. For the first time, Lancastrians face Yorkists at the battle of St Albans. The play ends with the king and queen in flight and the Yorkists contemplating the crown.