Henry, also known as Hal and portrayed by Timothée Chalamet, is the emotionally detached firstborn of King Henry IV, played by Ben Mendelsohn, of England. Rather than embracing his royal duties, Hal spends his days indulging in drinking, revelry, and jesting alongside his companion, John Falstaff, played by Joel Edgerton, in the lively streets of Eastcheap. The tides turn when his father unexpectedly informs Hal that his younger sibling, Thomas, portrayed by Dean-Charles Chapman, has been chosen as the rightful heir to the throne.
As tensions simmer in England, Thomas is dispatched to quell the rebellion led by Hotspur and his faction, who feel betrayed despite their loyalty to the royal lineage. They argue that with the Scots still in rebellion and the Welsh joining the fight, peace eludes the realm. However, Hal disrupts the plan when he arrives unannounced to confront Hotspur, depicted by Tom Glynn-Carney, in a dramatic duel. This intense conflict escalates into a gripping hand-to-hand combat, concluding with Hal triumphantly dispatching Hotspur using a dagger. Although he secures the victory, Thomas expresses his ire, accusing Hal of stealing his glory. Shortly afterward, Hal experiences loss when Thomas is killed in battle in Wales.
In a poignant moment, King Henry IV passes away with Hal by his side, leading Hal to ascend the throne as King Henry V. Not wanting to repeat his father's legacy, Hal curtails the cycle of animosity and seeks a path of peace with former adversaries, a choice seen by many as a sign of weakness. During the coronation feast, an insult from the Dauphin of France, played by Robert Pattinson, arrives in the form of a humiliating ball. Hal, however, spins this insult into a reflective nod to his past, waiting to wear the crown with dignity.
With wise counsel from his sister Philippa, played by Thomasin McKenzie, now the Queen of Denmark, Hal learns of the treachery that lurks among nobles who hide their true motives. When an assassin claims to have been sent by King Charles VI, played by Thibault De Montalembert, Hal's confidence wavers as French agents attempt to sway his noblemen, including Cambridge and Grey.
Guided by Chief Justice William Gascoigne, portrayed by Sean Harris, Hal realizes that to command respect, he must demonstrate strength. Thus, he declares war against France and delivers a grim fate to Cambridge and Grey. Motivated by trust, Hal appoints Falstaff as his chief military strategist.
As the English forces set sail for France, Hal leads with Falstaff beside him. Following their advance, they encounter a vast French army preparing for battle. Even as doubt brews among his advisors, Hal is determined. A strategic ploy devised by Falstaff—luring the French with a false advance—proves successful, allowing the outnumbered English forces to gain a victorious upper hand at the Battle of Agincourt. As the battle rages, Falstaff tragically falls on the front lines, while Hal faces the Dauphin in a personal combat that leads to the latter's humiliation.
After the chaotic but decisive victory, Hal and his army press further into French territory, eventually confronting King Charles VI who offers to surrender, along with the hand of his daughter, Catherine, portrayed by Lily-Rose Depp. Returning home with Catherine, Hal engages in a deep conversation with her, only to find their views on the war markedly different. She speaks frankly, challenging his justifications for the invasion and indicating the manipulative role of Gascoigne.
Haunted by the realization that he has been baited into conflict through deceit, Hal confronts Gascoigne, who unabashedly champions the idea that peace can only be achieved through conquest. In a moment of cold ire, Hal makes a fateful choice, culminating in the death of Gascoigne, before vowing to Catherine that he will always seek honesty in their relationship.
