It will be 10 years this weekend since the death of Princess Diana in a car crash in a Paris tunnel, prompting a tidal wave of mourning across the globe and, in Britain, condemnation of the royal family for its failure to grieve appropriately.

		"THE DIANA CHRONICLES" By Tina Brown Doubleday ($27.50)

Since then, the cult of Diana has continued to flourish even as her ex-husband marries his mistress -- whom Diana loathed and blamed for the breakup of her marriage -- and her two sons appear to have weathered the shock of her death. They have entered adulthood with some measure of maturity, despite the occasional clashes with paparazzi.

Just in time to make sense of it all is Tina Brown's crisply authoritative yet supremely dishy book. Published in May, it has inhabited best-seller lists ever since.

This is no trashy cut-and-paste job, however. Brown's interview subjects, she is quick to remind us, start with Prime Minister Tony Blair and go from there.

Some people hate this book, most notably British writer Sarah Bradford, author of two previous reports on Diana. In the Guardian, a London newspaper, she scorched Brown's book, claiming it offered little new information and recycled some of her own material.

Brown, in turn, claimed sour grapes, noting the "gratifying" reviews for her effort compared to Bradford's.

Indeed, during her own 30-year ascent to the top of the media elite in Britain and America, Tina Brown, 54, has so deeply schooled herself in the manners and mores of the rich and famous that she's a veritable Talmudic scholar on the subject of Diana and the various worlds she inhabited. They spanned the upper reaches of British society to America's royalty-worshipping culture to the fast-paced, deadly serious international world of AIDS charities, land mines and other issues.

Yet Bradford was right about one point: In "The Diana Chronicles," we have one chic, ambitious blond woman writing about another -- albeit from a very different social strata.

The daughter of a British film producer and of Laurence Olivier's former assistant, Brown grew up on the fringes of glamour. After graduating from Oxford, Brown, then 25, was named editor of Tatler magazine, the bible of Britain's aristocracy, just as the cultures of media, celebrity and high society were beginning to merge in a heady new brew.

Very often, this book feels as though it's as much about Tina Brown as it is about Diana, given her frequent use of the "I" word in relation to her subject, as in "I had lunch with her at the Four Seasons ...."

Brown may not have been in the Paris tunnel that August night, but she has dogged Diana's steps relentlessly since publishing photos of the shy pre-school teacher in 1981 in Tatler when it became clear that she was Prince Charles' choice to be his wife.

Later as editor of Vanity Fair, Brown was the first to break the story of the collapse of Diana and Charles' marriage -- as she is quick to tell us.

Brown's analysis of that fatally flawed union seems accurate, her sourcing impeccable, even if her over-the-top writing style occasionally veers into camp.

Of Diana's search for love and settling, at least temporarily, for Dodi Fayed, she notes, "for women over thirty-five, glamour has three Stations of the Cross: denial, disguise and compromise."

Then there's this gem, which starts out to be about Diana's appearance at that Four Seasons lunch and morphs into a bizarre observation about the size of celebrity heads: "Hillary Clinton's, for instance, has grown enormously since she was the mere wife of the governor of Arkansas. It nods when she talks to you like a balloon in the Macy's Thanksgiving Day parade. The years of limelight so inflated the circumference of Jackie O's cranium, it seemed her real face must be concealed by an oversized Halloween mask. If you looked into her eyes, you could see her in there, somewhere, screaming."

And that's just on page 3.

Still, this book does a credible job explaining what went wrong between Diana and Britain's royal family, and who's to blame -- even if we come away still unsure why, in the end, it's really important.

Brown's own trajectory has slowed of late: Talk magazine only lasted a few years, and "Topic A With Tina Brown,'' her little-seen show on CNBC, was canceled.

Her column for The Washington Post drew flak from critics who found it frivolous.

With this book, though, she's rebounded nicely, reminding us how supple and skilful a writer she really is, although in interviews she denied that "The Diana Chronicles" was "a gambit for reinvention rather than the passionate literary exercise that it was."

OK, Tina, if you say so.