The film stars Charlie Hunnam as the title character and Jude Law as the tyrannical king Vortigern who is attempting to kill him, with Àstrid Bergès-Frisbey, Djimon Hounsou, Aidan Gillen, and Eric Bana in supporting roles.

Uther Pendragon, the king of the Britons, infiltrates Mordred's lair during the attack and beheads him with the help of a unique sword forged by Merlin, saving Camelot.

The mage persuades Bedivere to take Arthur to a realm called the "Darklands", where he sees a vision of how the Demon Knight, revealed to be Vortigern, killed his mother.

He also witnesses his father sacrifice himself to save Arthur and entomb the sword in stone made of his own body, making him realize that he is indeed the rightful king.

Arthur learns Vortigern was responsible for persuading Mordred to attack Camelot, having grown jealous of Uther's popularity and wanting the throne for himself.

After 2004's King Arthur, Warner Bros. Pictures made multiple attempts to make a new film based on Arthurian legend: one was a remake of Excalibur (1981), helmed by Bryan Singer, while the other was a film titled Arthur & Lancelot, which would have starred Kit Harington and Joel Kinnaman in the title roles respectively.

[9] For this endeavour they hired director Guy Ritchie, who had himself wanted to make a King Arthur movie for several years.

[22] In April 2015, filming took place in Snowdonia, where locations used were Tryfan, Nant Gwynant near Beddgelert and Capel Curig.

[23] Early in July filming continued in the Shieldaig, Loch Torridon and Applecross areas of Wester Ross in the Scottish Highlands.

It was originally planned for an IMAX release on 22 July 2016, as evident in the Comic-Con trailer,[24] but was cancelled due to it being postponed and only received non-IMAX presentations.

[25] The film was shown at select AMC Theatres in a special preview on 27 April 2017, in a promotional event titled "King for a Day".

[33] In North America, the film was released alongside Snatched and Lowriders and was initially projected to gross around $25 million from 3,702 theatres during its opening weekend.

1 in an estimated 29 countries, including Russia, with openings to follow in the United Kingdom, France, South Korea and Australia.

The site's critical consensus reads, "King Arthur: Legend of the Sword piles mounds of modern action flash on an age-old tale – and wipes out much of what made it a classic story in the first place.

[25] Writing for The Guardian, Peter Bradshaw gave the film a generally positive review: "Guy Ritchie's cheerfully ridiculous Arthur is a gonzo monarch, a death-metal warrior-king.

Ritchie's film is at all times over the top, crashing around its digital landscapes in all manner of berserkness, sometimes whooshing along, sometimes stuck in the odd narrative doldrum.

But it is often surprisingly entertaining, and whatever clunkers he has delivered in the past, Ritchie again shows that a film-maker of his craft and energy commands attention, and part of his confidence in reviving King Arthur resides here in being so unselfconscious and unconcerned about the student canon that has gone before.

It is a grim and stupid thing, from one of the world's most successful mediocre filmmakers, and if Shakespeare's King Lear were blogging today, he'd supply the blurb quote: 'Nothing will come of nothing.'.

"[43] Matt Zoller Seitz of RogerEbert.com gave the film one-and-a-half out of four stars, stating that despite the potential for a revisionist King Arthur story with "[t]he Ritchie sense of style", the overall problem is the film's lack of modulation: "Ritchie keeps rushing us along for two hours, as if to make absolutely certain that we never have time to absorb any character or moment, much less revel in the glorious, cheeky ridiculousness of the whole thing.

[46] King Arthur: Legend of the Sword was nominated in four categories at the 2017 Golden Trailer Awards: "Throne" (Open Road Entertainment) for Best Action, "Story" (Wild Card) for both Best Original Score and Best Sound Editing, and "Rules 60" (Wild Card) for Best Fantasy Adventure TV Spot (for a Feature Film).

[47][48] At the Golden Reel Awards 2017, the film received a nomination for Outstanding Achievement in Sound Editing – Music Score.