July 4 looms. You know, that holiday where we celebrate our independence from kings and queens across the ocean.

So why are we so obsessed with the regal monarchs of days gone by?

"These things tend to go in cycles. This period is very dramatic and you've got some vivid larger-than-life characters," said popular historian and novelist Alison Weir, whose latest book is "The Lady Elizabeth." "Power is such a sexy thing."

The latest in a long, long line of film adaptations would be "The Other Boleyn Girl," which quickly hit the top rental lists after it was released two weeks ago. It joins a spate of recent films and series based on the era of Tudor kings and queens of England (roughly, the 1500s), and primarily focused on Henry VIII and his daughter, Elizabeth I.

Just in the last two years, we've seen the entire gamut of Elizabeth's life on the screen. There was the young woman (Anne-Marie Duff) in Masterpiece Theatre's "The Virgin Queen."

Oscar-nominated Cate Blanchett took Bess into middle age in "Elizabeth: The Golden Age."

Helen Mirren won an Emmy for her portrayal of the aging monarch in HBO's "Elizabeth I."

Of course, one can't forget Showtime's uber-sexy, uber-flashy "The Tudors," with Jonathan Rhys Meyers as Henry VIII. The first season is out on DVD; no release date has been given for the second season that just finished.

Then there's the BBC's own miniseries version of "The Other Boleyn Girl," which was recently released here on DVD. Sadly, it was not titled "The Other Other Boleyn Girl."

Clearly, there's a market for this material. But, from a historical perspective, does anybody get it right?

Not really, says Weir. Too many films have bad guys who were actually good guys, murders that never happened, scenery or costumes that are designed for no specific time period or colors that hadn't been invented yet.

"As a historian, I'm becoming so horrified by what I see these days," she said in a phone interview while on a recent U.S. book tour. "It's so sloppy and it doesn't need to be."

Weir has written exhaustively on the subject for nearly two decades. She has written biographies of Henry VIII, Elizabeth I, "The Six Wives of Henry VIII" and "The Children of Henry VIII."

She knows a thing or two about how this stuff could be presented, but isn't. "The Other Boleyn Girl" is just the latest to get her goat. Not the least of reasons was how it took events over the course of many years and made them seem like a couple weeks.

"That was a travesty," she said. "I got an e-mail from someone saying they were so tired of historians saying, 'This is a travesty,' that it was entertainment," Weir said. "I can't think of the number of historical films I've sat there cringing through. People are being sold so short. It's a wonderful story; you couldn't make it up."

She was particularly frustrated by a recent "Henry VIII," which starred Ray Winstone as the monarch with a working-class Cockney accent. She was hired as a historical adviser, but later asked that her name be taken off the credits because her advice was ignored.

Weir said she enjoyed "The Tudors" as a drama and was impressed by Rhys Meyers, despite the fact that he looks nothing like Henry VIII.

"I really got a sense from the performance that this was Henry," she said. "They just aimed it at such a young audience so everybody is going to look far too young, and they did."

That leaves one big question. Does anybody get it right?

Most certainly, Weir says. You just have to go back in time a bit.

Glenda Jackson nails it, Weir says, in the 1971 BBC/Masterpiece Theatre series "Elizabeth R."

It won five Emmys, including for best dramatic series and for Jackson's performance.

"She's fabulous. Her acting is so consummate," Weir said. "She captures every facet of Elizabeth's complex character. She was lucky with the script, because it was based on original sources, so she was saying the words she should be."

The series itself is more than eight hours, and the DVD extras would please any Tudor-phile. Besides historical commentary from Weir throughout, an entire extra disc includes more from Weir, an interview with Jackson, an A&E documentary, galleries and a who's who.

Keith Michell played Henry VIII in two BBC series that later came to home video in the U.S. The one focusing on the monarch himself was available on VHS but hasn't yet come to DVD, but "The Six Wives of Henry VIII" from 1970 is out on DVD.

"It's utterly definitive. You think it is Henry. It's wonderful," Weir said.

Relatively recent films don't escape Weir's praise, though. Judi Dench only appeared for a few minutes as Elizabeth in "Shakespeare in Love," but it did the trick, Weir said. The role earned Dench an Oscar for Best Supporting Actress.

"I loved it," Weir said. "Wonderful film, and she deserved that award."