The play begins in England, but shifts to France in Act 2, Scene 4, where the rest of the play takes place. Much of the diplomatic action occurs in the English and French palaces, where kings and their political advisors make decisions about foreign policy, military campaigns, and peace treaties. The Henry plays are also famous for the tavern scenes, where seedy characters like Bardolph, Pistol, Nim, and Mistress Quickly get rowdy. These kinds of scenes are limited in Henry V because everyone goes off to war, where the most important action goes down. The battle scenes occur in Harfleur, France (where Henry's troops capture the town) and on the fields of Agincourt, France.
As the Chorus frequently reminds us, Shakespeare's staging options are pretty limited – since it's impossible to cram thousands of troops and horses onto a small stage, we're often asked to use our imaginations. In the Prologue, the Chorus asks
[...] can this cockpit hold
The vasty fields of France? or may we cram
Within this wooden O the very casques
That did affright the air at Agincourt?
The answer is no. The theater can't contain the fields of France so the audience has got its work cut out for it. Lucky for us, there have been some pretty nifty technological advances since Shakespeare wrote Henry V. When adapted into film, the play's setting can be pretty incredible.
The play was written around 1599, but it portrays events that occurred immediately before and after the Battle of Agincourt (October 25, 1415), which just so happened to occur on St. Crispin's Day, the feast day of the martyred twins, Saints Crispin and Crispinian. Like we've said elsewhere, the events in the play speak to some contemporary (Elizabethan) issues. As Shakespeare's original audiences watched Henry wage a war with France, they would have been reminded of their own long-standing problems with Spain and a recent uprising in Ireland, the Earl of Tyrone's Rebellion (1594-1603). We also want to note that the tavern scenes involving Pistol, Mistress Quickly, and Bardolph look and sound a lot like what have gone down in any Elizabethan tavern, not a medieval inn.