Out of the depths of the cheesy cinematic realms of the 1960s comes the, ahem, “real” backstory of King Arthur and his legendary sword, Excalibur. After the sack of the city by Goth barbarians in AD 460, the last emperor of Rome, the preadolescent Romulus Augustus (Thomas Sangster: Tristan & Isolde), flees for Britannia with the commander of his guard (Colin Firth: Nanny McPhee) and the requisite motley band of soldiers and hangers-on, like the she’s-not-a-man-baby warrior Mira (Aishwarya Rai: Provoked: A True Story) and Romulus’s philosopher/teacher (Ben Kingsley: You Kill Me). In their care: the mighty sword of the caesars around which a royal prophecy is woven. Mythmaking ensues. No one embarrasses himself — except for Kingsley, whose accent is as wildly all over the place as the movie’s tone: now it’s an historical epic! now it’s a medieval comedy! — and the Sangster kid really is quite appealing, actually. But the plot is beset by outrageous coincidence, simple idiocy, and a sense of drama that is ridiculous, and the whole endeavor is bereft of anything approaching the movie magic it is clearly desperate to evoke. (The echoes of The Lord of the Rings are particularly mysterious: cuz really, you don’t want viewers longing for the flair of Peter Jackson when they’re watching this.) The few noteworthy touches — like how Kingsley’s not-yet-Merlin inspires awe not with wizardly magic but the sleight-of-hand brand — are overwhelmed by the incoherently directed action sequences, which are made even more disjointed by the choppy editing obviously intended to reduce the film’s violence and, it seems likely, to bring the movie from an R rating. To be fair, though, the costumes are fantastic, and everyone looks FABulous.