It takes a certain amount of nerve to attempt a new adaptation of the life of England’s King Henry V. William Shakespeare has effectively had Hal’s story sewn up since about 1599, with his rousing and patriotic account standing as pretty much the most famous of his history plays. It seems even braver to base that new adaptation on Shakespeare’s own work, but reframing and reimagining characters and finishing it all off with entirely new, but still highly poetic dialogue. That writer/director David Michôd and co-writer/actor Joel Edgerton have succeeded in their attempt is not the most impressive part – what surprises is just how powerful and effective their film The King really is.

They introduce Prince Hal (Timothée Chalamet), drunk and disgraced, carousing with the similarly rough John Falstaff (Edgerton). Hal has been disinherited by his ailing warmonger father (Ben Mendelsohn) in favour of his younger brother Thomas (Dean-Charles Chapman). When the foolhardy Thomas dies in battle, and Henry IV passes away soon afterwards, an unwilling Hal is forced to take the throne and face both a divided kingdom and growing French provocation against it.

The King is a heavily fictionalised presentation of history, ascribing new motivations to characters, shifting events and deaths back and forth to suit Michôd and Edgerton’s narrative, and siding with good drama over accuracy whenever suitable. That is not necessarily a fault in the film, since the resulting drama is spectacularly plotted and timed, creating powerful character arcs for Hal, Falstaff, and the English royal court. Hal is presented as a pacifist, only driven to invade France after extended provocation. Chalamet’s performance is fantastic, showing off a complexity and an internal conflict that Shakespeare never had the need to create. Shakespeare’s character of Sir John Falstaff is made more realistic, with an actual intelligence to him and a stronger background in warfare and strategy. Edgerton achieves a huge amount in the role, like Chalamet presenting a complex human being rather than something superficial.

The film’s periodic action scenes emphasise realism: medieval warfare is shown to be brutally violent and periloisly clumsy, as soldiers use swords less to cut and more to beat enemies to death, and knights stagger under the weight of their armour and risking fatally slipping on the muddy battlefields. It was Mel Gibson’s 1995 epic that revolutionised medieval combat on screen, and The King has a visible debt to that work. You can also see the influence of HBO’s popular series Game of Thrones in how these violent, bloody conflicts play out. They are visually excellent, but the film’s true strength is in the courtly intrigue that drives them to occur. The King boasts some pitch-perfect casting: Mendelsohn as a cruel and unpleasant Henry IV, Robert Pattinson as a marvellously camp Dauphin, Lily Rose Depp as a blunt and whip-smart Princess Catherine, and particularly Sean Harris as the manipulative political advisor Lord William.

For fans of historical drama and medieval action, The King is a must-see. The dialogue carries power, the performances invite the audience’s engagement, and the cinematography by Adam Arkapaw (Assassin’s Creed, Macbeth) is atmospheric and involving. This is one of the strongest pictures of the year.