"Diana," a biopic about the late Princess of Wales premiered in London on Thursday night, with Naomi Watts walking down the red carpet dressed in a white Versace gown.

Watts portrays the princess in her last two years, after divorcing Prince Charles, chronicling her life with lover Hasnat Khan, before finally perishing in a car crash. Several fans have observed that Naomi Watts had been perfect for the role, but the actress have always had her reservations.

She had famously turned down the role several times before finally agreeing to sign on, afraid of the pressure of portraying one of the most beloved women of Britain.

Watts has said that she worked hardest on emulating Princess' Diana's voice and mannerisms, reportedly taking six to eight weeks just to get the voice right.

"Diana" opens in US theaters on November 1, but recent reviews of the film's first few showing in London have not been very forthcoming.

The film drew mostly negative reviews from British critics, who cited concern with the script and the dialog, and even the lead's performance.

Some of the reviews have called the script "embarrassing," and while others praised Watts with consolatory remarks, several critics have not hesitated to call the movie "atrocious and intrusive."

The Telegraph's review concludes that the film had been "hardly fascinating," that it had not opened up anything new about the princess' life, which had already been widely documented and speculated on upon her engagement to the Prince of Wales up to her violent death.

Joining Naomi Watts in the cast are Naveen Andrews, who portrays Diana's lover, Cas Anvar as Dodi Fayed, Laurence Belcher as Prince William, Douglas Dodge as Prince Harry. Rounding up the cast are Douglas Hodge as Paul Burrell, butler to the princess, Geraldine James as Oonagh Toffolo, and Charles Edwards as Patrick Jephson.