THE MADNESS OF GEORGE III. By Alan Bennett. Directed by Nicholas Hytner. Designer Mark Thompson. Lighting by Brian Ridley. Music by Kevin Leeman. With Nigel Hawthorne, Julian Wadham, Clive Merrison. At the Rich Forum, Stamford, Conn., through Sept. 25. Moving to the Brooklyn Academy of Music Sept. 28-Oct. 10. Seen at Wednesday evening's performance.

IN A BRAVURA, nerve-naked performance as the British king credited with losing the colonies to America, Nigel Hawthorne in "The Madness of George III" raises royal exhibitionism to heights that make the recent Buckingham residents look comatose by comparison. Enacting King George's deterioration from a hereditary metabolic disorder known as porphyria, Hawthorne must dither before the royal household in excrement-soiled nightclothes, boldly molest a lady-in-waiting, babble obscenities in two languages and be strapped into therapeutic instruments of torture.

George's seeming insanity and its perilous impact on an already crumbling parliamentary support system form the political nexus of Bennett's sprawling evening, which marches into the Brooklyn Academy of Music Sept. 28. The primary personal tensions emerge from George's one-on-ones with an odd Anglican clergyman named Dr. Willis (Clive Merrison), who employs an early form of aversion therapy to cure the king. The seriocomic comingling of personal with political provides enough fodder for a trilogy, and you feel the weight. While "The Madness of George III" brims with eccentric characters, vervy performances, fevered encounters, historical minutiae and Bennett-briny wit, it never quite sweeps us off our feet.

It isn't that the internecine struggles of George's domain are awash in overcomplexity. Bennett delineates the various factions with aclarity and fondness for the broad stroke that, if anything, suffers from redundancy. On the one side are the king's faithful Tories, represented by the businesslike prime minister, William Pitt (Julian Wadham). In a subtle and touching characterization, Windham cocks his head at a fixed angle away from George, a gesture of deferential respect and, as we later discover, an expression of pain at the memory of his own mad father.

On the opposing end are the Whigs, who see in the king's illness the perfect opportunity to rid themselves of George and install his two sons, the dandified prince of Wales and the foppish duke of York. "They come in pairs," sighs one of the Whigs, and chubby Nick Sampson and willowy Julian Rhind-Tutt play the brothers as an 18th-Century vaudeville duo, Laurel and Hardy in breeches.

Bennett pushes them on for a laugh and a snarl one time too many, as he does a trio of quack doctors who submit George to a marathon course of bleeding, stool samples and painful blistering therapies. "The medical profession hasn't changed much," quipped a man behind me - a cheap shot, to be sure. But, as with most historical drama, Bennett's play relies on our savvy for drawing the link between past and present. "The Madness of George III" necessarily loses much of its resonance when lifted away from its land of origin, where foggy-headed princes of Wales are an ongoing concern, and folks know a Fortnum & Mason joke when they hear it.

The central connection Bennett wants us to make, of course, is metaphorical: George's mysterious "madness" as a stand-in for England's present, intractable socio-economic malaise. If that doesn't light your fire, it's possible simply to revel in the meticulous calibration of Hawthorne's performance, as he lets the floor drop from George's self-control in painful increments. "I'm not mad, I'm just nervous," he insists (not inaccurately) as he glides from a fastidiously groomed, vigorously good-humored leader to the pathetic image of a pig in slop.

Hawthorne and his author play their most thrilling hand as George reads from "King Lear" in Willis' accidentally ingenious stab at recreational therapy. George performs with a soaring empathy that can only come from having lived Lear's downfall. The reading has a cathartic effect, snapping George back to his old, healthy self. "I've always been myself, even when I wasn't," he says. "Now I seem myself."

This is the tenuous crux of Bennett's play: The fragility of a royalist society that depends so much on the appearance of well-being among its rulers. At least Nicholas Hytner's smart production backs it up with gleaming surfaces: Selina Cardell's bemused queeen Charlotte and Richenda Carey's unflappable Lady Pembroke. Moving the production with a cinematic fluidity is Mark Thompson's design of pull-curtains, dropping walls and wooden staircase, backed by a giant gold picture frame. "The Madness of George III" is suitable for framing, a polished canvas has the overall effect of a grand, fussy still life.