What Is The Main Plot Of Shakespeare's Play Henry V?

Two meddlesome priests manage to persuade the King that according to an ancient law, the King of England Henry is entitled to the throne of France.

Henry asks France for their crown and they insult him and remind him of when his faults as a younger man.  Henry builds an army and heads for Southampton.  A plot to murder Henry is uncovered and Henry clever makes each traitor indict themselves.

In France, Henry's army meets stiff resistance at the castle of Harfleur.  The English army are beaten back time and again, Henry gives his famous 'Once More Unto the Breach' speech and warns the occupants of the castle to lay down their arms or he will kill everything inside.  This they do.

At the field of Agincourt, the English army, tiny, numbering perhaps only 500 hundred, meets thousands of French soldiers, although much of this story is true, Shakespeare makes the English seem more heroic by stacking the odds against them.  On the battlefield, by God and by valour, the English win the day, using their bowmen.

After the battle, the French King consents to his daughter Katherine marrying Henry and Henry woes Katherine in broken French and Shakespeare's sweetest puns.

The final words are given to the narrator called the Chorus of the whole piece, who has provided a narration for much of the transitions.  He speaks of the problems that face Henry in the future and how the French crown passes back to the French once more through Henry's son.