The full story with reduced dialogue for easier reading.
It's the 15th century and the Archbishop of Canterbury, worried over impending legislation that would effectively rob the Church in England of its power and wealth, convinces Henry V to forego this pursuit in favour of laying claim to France.
Armed with a legal technicality, Henry means to take the throne of France by whatever means necessary.
The Dauphin's insulting response (sending an ambassador with a gift of tennis balls) convinces Henry that the French will only respond to war.
He gathers his army to invade France, but he must also make certain that he leaves enough troops in England to quell any potential rebellions.
This leaves him with a relatively small invasion force.
Henry must deal with one plot before even crossing the Channel.
Lords Cambridge, Scroop and Grey are discovered to be conspiring to assassinate Henry (instigated by the French).
Henry makes a very public example of all three, arresting them in person and seeing to their execution.The army then lays siege to Harfleur, capturing it after heavy losses. Henry wants to take his army out of France before the onset of Winter, but the French are certain they can teach the young king a humiliating lesson on the field of battle.
This stiffens Henry's resolve and he decides that, if the French want a decisive battle, they'll get it!
While in camp, Henry disguises himself as a common soldier and mingles with his troops before the battle.
He talks candidly with his men and they with him. The men may be a little wary of their king, but their willingness to fight the French army is undaunted.
Next day at Agincourt, Henry makes the stirring St. Crispin's Day speech, knowing his army is outnumbered five to one.
But, aided by the longbows of his archers, Henry wins the day.The French sue for peace, which Henry grants on his own terms.
These terms are spelled out in the Treaty of Troyes - Henry will marry Princess Katharine of France and will be named as heir to the French throne.
England and France will thus be united in peace.