Henry IV Part 2: Novel Summary: Act III Scene 1

Act III Scene 1
The King enters in his nightgown, with a page. He gives the page letters to deliver to the Earls of Surrey and Warwick.
After the page exits, Henry gives expression to his troubled state of mind. Weighed down by the cares of state, he is unable to sleep.
Warwick and Surrey enter. Warwick is optimistic about the military situation, and expects Northumberland soon to be defeated. The King, however, is in a more reflective mood. He looks back over the history of the past ten years, noting how former friends became deadly rivals. He recalls how Richard II, the king Henry IV overthrew, predicted that Northumberland, who had helped Henry IV gain the throne, would eventually rebel against him.
But then the King gets down to business. He has heard that Northumberland and York have a force of fifty thousand men. Warwick discounts this, saying there are only half that number. He thinks victory will be easy. He also announces that the leader of the Welsh rebels, Glendower, is dead-news that is sure to please the King.
The King resolves that once these civil wars are over, he will journey to the Holy Land.
Analysis
The play is nearly half-way through, but this is the first time we have seen the King. Contrary to what the rebels might have led us to expect, Henry IV makes a favorable impression. He is a serious, reflective man, suffering under the heavy burdens of kingship.
And yet Shakespeare does not allow the audience to forget that Henry IV seized the crown by overthrowing Richard II, the legitimate king. The playwright accomplishes this by having the King look back at past events, at how Northumberland had helped him overthrow Richard II. Pointedly also, he recalls Richard's prediction that Northumberland would eventually turn against him.
Shakespeare wants the audience to keep this in mind because he shared the common Elizabethan view of this period of English history. They believed that the overthrow of Richard II, the rightful King, was a crime, and the civil wars and disorder that followed during the reign of Henry IV were the consequences of this crime.