Although the play had to be heavily edited for length, the adapted screenplay remains overall true to its source material.
The film opens with Chorus (played by Derek Jacobi), who wears modern costume, introducing the play to the audience, before opening the doors onto the set where the play takes place, and the show commences.
Henry V is set in 15th century England, in the midst of a bitter national conflict with France. Henry V, the young King of England, is convinced that he is the rightful heir to the French throne. When Henry consults the Dauphin, or the eldest son of the King of France, the Frenchman gives Henry a chest full of tennis balls as a joke. Gravely insulted, Henry begins to make preparations for war against France.
On his march to France Henry happens upon three known traitors posing as Englishmen in the street. He has them captured arrested by his uncle, the Duke of Exeter, and orders that they be hanged for treason before continuing towards France. King Charles IV of France, has learned by this time of Henry’s approach. He is worried that England will invade France, as has happened previously so many times in the nations’ histories. The Duke of Exeter appears and warns Charles that he must surrender the crown to Henry or English forces will attack. Charles says he needs the night to think it over and will respond the next day.
The first town which the English forces come across is Harfleur, which is heavily fortified against attack. Henry delivers a rousing speech to his troops and they conquer the town. King Charles’ daughter Lady Katharine, endeavors to learn English. She can see how nervous her father is and recognizes that English invasion is imminent. Charles finally orders his army to retaliate against the English forces, which have been delayed by rain and illness on their journey towards Calais. When the French ambassador Mountjoy, intercepts Henry and demands that he surrender, Henry refuses despite his army’s weakening condition. Both sides prepare for inevitable battle.
The night before they are due to battle with the French forces, Henry puts on a disguise and walks around his troops’ encampment to get an idea of their condition. He gets in a fight with a soldier named Williams, who argues that any deaths which come as a result of battle the next day will be Henry’s fault. Henry, disturbed by his soldiers’ bitter attitudes towards him, delivers a monologue in which he begs God for help during battle.
Morning comes, and Henry rallies his troops with the famous “St. Crispin’s Day Speech”. Despite being heavily outnumbered, the English manage to force the French to surrender, but not without great losses on both sides. The battle is bloody and many innocent lives are lost when the French set fire to the English encampment. Mountjoy surrenders on behalf of the French and the countless bodies of dead soldiers are removed from the battlefield.
Henry strikes up a romantic relationship with Katharine and is crowned King of France. Chorus concludes the film by telling the audience that Henry V shed much blood in order to win rule over the french, only to have it lost years later by his successor Henry VI.