The Duke of Gloucester does not want Henry giving up two fiefs to France to wed Margaret who has, in Gloucester's opinion, a lack of dowry.

Not wanting his plans to go awry, Suffolk begins to plot against Gloucester. Part of Suffolk's attempt to get at Gloucester, the only real supporter of Henry, Suffolk has Gloucester's wife arrested for witchcraft.

Meanwhile, York is lurking in the shadows, still believing that he has claim to the throne of England and that Henry should not be king.

Eventually Gloucester is arrested on false charges and King Henry orders a trial. While all of this is going on York is sent to Ireland to stop a revolt. Once York is there he meets Jack Cade whom he uses to garner him support for the throne of England so he may usurp Henry. If Cade should succeed, York has an entire army at the ready. Things in the play get busy from here.

Gloucester is murdered and Henry banishes Suffolk for the deed. Margaret begs for Suffolk as she has been having an affair with him, but the king does not listen. Suffolk is captured by pirates and put to death while he is en route to France.

Jack Cade's rebellion back in Ireland is gathering support and he marches on London, where Henry stages a retreat.

Buckinham confronts this force with his army and tells Cade's men that he will grant pardons to all who will renouce Cade who then flees and is killed five days later while foraging in a private garden for food.

York returns from Ireland and demands that Henry arrest Somerset or else his men will continue fighting. Henry does just this but Margaret lets Sommerset go almost as quickly, which makes York declare war on the king.

Finally, Richard, son of York kills Somerset at the Battle of St. Albans, and the York supporters give chase to King Henry and Margaret, which leads into Henry VI, Part III.