WHEN N.Y.'S MURDERIN' CANYONS ROARED.

Byline: Glenn Whipp Film Critic

MARTIN SCORSESE'S ``Gangs of New York'' takes all the themes that have been coursing through the great director's body of work - class, religion, man's brutal nature - and sets them against a wonderfully rich historical backdrop on the meanest streets that New York has ever seen.

The movie is an epic summation of a master's career - an endlessly fascinating, landmark movie that is as bold as anything the cinema has seen in years. Needless to say, it is the year's best film.

At first glance, ``Gangs'' is a story of revenge set among the gang warfare that plagued Manhattan's seedy Lower East Side - an area known as the Five Points. But Scorsese has much larger ambitions than to simply craft a bloody period piece. ``Gangs'' spans the years 1846-63, but is set predominantly in the Civil War era, a crossroads in American history full of prejudice, political corruption and class warfare. The movie vividly illuminates this time while subtly noting parallels in modern America.

The film's story follows a young man, Amsterdam Vallon (Leonardo DiCaprio), looking to avenge the death of a loved one at the hands of William Cutting, aka ``Bill the Butcher'' (Daniel Day-Lewis, in an incendiary performance that will be talked about for years). The Butcher (based on a real person) runs the Five Points, heading the American-born Nativists gang. He hates immigrants, at one point telling New York's famously corrupt political kingpin, William ``Boss'' Tweed (Jim Broadbent, great as usual): ``If only I had the guns, Mr. Tweed, I'd shoot each and every one of them before they set foot on American soil.''

Young Vallon ingratiates himself with Bill, becoming something of a protege and, oddly, learning to become the kind of man that could eventually bring down the savage Butcher. In the process, he meets Jenny Everdeane (Cameron Diaz), a beautiful pickpocket whose connections to Bill put her in the middle of the inevitable conflict between the two men.

The film's screenplay, credited to longtime Scorsese collaborator Jay Cocks, along with Steven Zaillian (``Schindler's List'') and Kenneth Lonergan (``You Can Count on Me''), turns the relationship between Vallon and Bill into a fascinatingly ambivalent one. As Vallon notes: ``It's a funny feeling being taken under the wing of a dragon. It's warmer than you think.'' Bill, meanwhile, in a riveting midmovie monologue, confides to Vallon that he considers him a son.

But as ``Gangs'' gradually unfolds and its interests move from personal to cultural, we see that the cocksure Bill has a more dangerous enemy - Boss Tweed of the notoriously corrupt Tammany Hall. Bill looks at the daily arrival of thousands of Irish immigrants to New York as an abomination; Tweed sees votes. The federal government sees draftees to fight the Confederates.

Scorsese visually illustrates the dynamic as only he can, his camera following young men disembarking from their journey across the Atlantic, then being immediately conscripted and put on a troop ship. The shot - a single - ends with the sight of cranes lifting the troop ship's cargo: scores of coffins containing Union soldiers.

It's an unforgettable image in a movie full of fantastic visual flourishes (the film's 15-minute opening gang fight is jaw-dropping) that combine an urgent intensity with poetic beauty. It all culminates in a final gang battle that takes a back seat to the brutal Draft Riots of 1863, when the Civil War came to New York and despots far and wide invoked God's name for their cause.

Two more things of note: Day-Lewis is so good, so volcanic, as the strutting, elongated gang leader that he seems to be acting in a separate stratosphere from the rest of the cast (who are all quite capable, by the way). We've seen him inhabit roles before with his ferocious power, but nothing could prepare us for the extraordinary work here. He succeeds in revealing not only the savagery of the Butcher, but also the peculiar nobility of the man. Simply amazing.

The same can be said for production designer Dante Ferretti's awe-inspiring re-creation of the Five Points. Built on a 15-acre soundstage in Rome, Ferretti's Five Points reveals a New York that lives up to Vallon's description: ``It wasn't a city. It was a furnace where a city might one day be forged.''

And ultimately, that's what ``Gangs'' is about: the birth of both a city and a nation. The wild frontier of America's bloody past has been paved over, but the back-stabbing, government corruption and class struggles contained in the country's dark heart remain. We've survived, but it's still a jungle out there, boyo.

GANGS OF NEW YORK - Four stars

(R: intense strong violence, sexuality, nudity and language)

Starring: Leonardo DiCaprio, Daniel Day-Lewis, Cameron Diaz, Jim Broadbent.

Director: Martin Scorsese.

Running time: 2 hr. 48 min.

Playing: Wide release.

In a nutshell: Martin Scorsese revisits the mean streets of America's past, and the results are spellbinding.