A would-be summer blockbuster is not an ideal forum for teaching history, especially when the lesson is skewed by contemporary political correctness. That's the main reason King Arthur's painstaking effort to retell the Arthurian legend with historical verisimilitude never comes alive.

The mood is undercut from the beginning with text proclaiming how the lore surrounding Arthur is basically bogus, concluding: "Recently discovered archeological evidence sheds light on his real identity." Such special pleading is unnecessary if the story about to be told is compelling on its own merits. The filmmakers -- action producer Jerry Bruckheimer, director Antoine Fuqua (Training Day), and screenwriter David Franzoni (Gladiator) -- try too hard.

Around 450 A.D., the Knights of the Round Table are conquered Sarmatian warriors serving the Roman Empire in Britain under the command of the half-Roman, half-British Arthur (Clive Owen). They're concluding fifteen years of service but a Bishop representing Rome assigns them one last, perilous task -- go north of Hadrian's Wall and rescue a Roman family from the invading Saxons. 

Guinevere (Keira Knightley) is a native princess who joins the self-fashioned freedom fighters on their mission, which inevitably evolves into repelling the Saxons. This band, with grudging help from Merlin's forest-dwelling tribes, spreads the gospel of peace, equality, and tolerance. Arthur is to ancient Britain what Martin Luther King and Malcolm X were to America in the 1950s and '60s. He preaches about the "gift of freedom" and has a sharp sword to deliver it. Not only is he an open-minded Christian, he's apparently a believer in the Civil Rights Act of 1964, dedicated to abolishing slavery and bigotry wherever he finds it.

Projecting modern values onto history isn't problematic by itself. It's the how and not the what; it needs to be done with more subtlety. Having Arthur go around crying "freedom"  (not to mention "peace") makes him sound like George Bush trying to justify the invasion of Iraq.

Likewise, emphasizing one aspect of a well-known story at the expense of others is to be expected. But ditching the love triangle between Arthur, Guinevere, and Lancelot (Ioan Gruffudd) drains this story of romance altogether. Knightley's Guinevere is a guerilla fighter painted up to look like a Lost Boy from "Peter Pan" during hand-to-hand combat with the Saxons. Here, geopolitics gives rise to the so-called love story, not the other way around.

It's hard to become attached to the major characters because, despite being proficient in battle, they're incredibly idealistic and theoretical. Comic relief is provided by one knight (Ray Winstone) who repeatedly jokes about his procreative powers, evidenced by a brood of bastard children. In addition to being anachronistic, the script is often dully portentous. Before lying with Arthur, Guinevere says, "What tomorrow brings, we cannot know." That open-ended pick-up line might work on the gloomy Arthur but it's not going to grab audiences. 

You can't fault the performances. Filmmakers had to know they would get a relatively starchy Arthur when they cast the tightly wound Owen. And while aspects of the plot, setting, and fairly violent action will remind viewers of Braveheart  and Gladiator, the production owes an obvious and unflattering debt to The Lord of the Rings trilogy. The one battle sequence that stands out takes place on a frozen pond where the outnumbered Sarmatians face the Saxons for the first time.

King Arthur's well intentioned sheen of historical veracity just isn't engaging. The movie's publicity tag line is "The Untold True Story That Inspired the Legend." Assuming it is true, there’s a reason it was left untold. Legends are pared down or distorted for good reason, namely, entertainment value. Don't be ashamed if you prefer Camelot.

(Released by Touchstone Pictures and rated "PG-13" for intense battle sequences, a scene of sexuality and some language.)