The ensemble cast included Sam Neill, Miranda Richardson, Isabella Rossellini, Martin Short, Helena Bonham Carter, Rutger Hauer, James Earl Jones, John Gielgud, and a then-unknown Lena Headey.

Nicholas Clay and Robert Addie, who play Lord Leo and Sir Gilbert respectively in this miniseries, had both previously appeared in John Boorman's 1981 film Excalibur as Lancelot and Mordred.

Paul Curran, who played the adult King Arthur here, also played Kay alongside Jason Connery's Merlin in the unrelated television film Merlin: The Quest Begins, released the same year.

The intro sequence showing Sam Neill riding a horse was filmed at Ynys Gifftan.

Illustrator Alan Lee served as the film's conceptual designer, and the story was written by Edward Khmara with a teleplay by David Stevens and Peter Barnes.

Unlike other Arthurian films such as Excalibur, Knights of the Round Table, and First Knight, which used High or Late Medieval-style weapons and armor, this production aimed for partial historical accuracy by using Dark Age and Early Medieval Celtic and Roman-style weapons and armor, including Iron Age swords, mail, scale, and leather.

Despite its attempt at historical grounding, the film contains anachronisms, such as Roman lorica segmentata armor appearing years after it was actually discontinued, and Uther invading from Normandy despite the story predating the Viking age and the Norman colonization that gave Normandy its name.

The original U.S. television broadcast achieved record audiences of an estimated 70 million viewers, with The New York Times describing the ratings as 'magical'.

The miniseries received 15 Emmy Award nominations and won four, for Outstanding Art Direction, Outstanding Costumes, Outstanding Makeup, and Outstanding Special Visual Effects.

A sequel, Merlin's Apprentice, was filmed by Hallmark Entertainment in Vancouver and broadcast on the Hallmark Channel in 2006, with Sam Neill and Miranda Richardson reprising their roles, though Richardson played a somewhat different role.