Naomi Watts had a tall order to fill when she signed on last February to play the late, beloved Princess Diana in upcoming biopic Diana. But judging by the British actress' careful elocution and nuanced gestures in a newly released trailer for the film, Watts has deftly stepped up to the task.

In the clip, Watts, 44, dons a blonde wig and various lookalike outfits to play the "People's Princess" in the film, which will follow the last two years of the late royal's life.

"Sometimes the legend is not the whole story," the tagline for the film scrolls across the screen, between shots of Watts as Diana looking regal and shucking off her pumps after a long day making public appearances.

The Oliver Hirschbiegel-helmed film will focus largely on Diana's romance with Pakistani heart surgeon Hasnat Khan, whom the late princess dated from 1995 to 1997. Lost actor Naveen Andrews will play the man whom friends have called Diana's "true love."

"Diana was madly in love with Hasnat Khan and wanted to marry him, even if that meant living in Pakistan," Jemima Khan, the former wife of Hasnat's distant cousin Imran Khan, told Vanity Fair for the magazine's September cover story. "And that's one of the reasons we became friends."

In the trailer for the film, Diana is shown slyly suggesting that the doctor join her for a bite after his hospital shift.

"I don't know how to reach you," Andrews as Dr. Khan says.

"I'm like most people, I have a mobile," she responds. "Actually, I'm not like most people. I have four."

Diana is due out in the U.K. on Sept. 20, and will be released in the U.S. on Oct. 10.