The first full trailer for the upcoming Princess Diana biopic has been released. Naomi Watts tackles the role of playing the celebrated royal and proves that she was the right actress for the job, even if it scared her at first. "There’s a huge amount of pressure and I tried to say no a few times since this movie is going to be so open to public opinion and that’s a scary thing for an actor to subject herself to," she said.

Diana, from director Oliver Hirschbiegel, focuses on the final two years of the late princess’s life after her divorce from Prince Charles. Special attention is given to Diana’s relationship with heart surgeon Dr. Hasnat Khan (played by Lost actor Naveen Andrews).

Watts, donning a blonde wig, exudes the grace and elegance the late princess was known for, portraying Diana during a tumultuous time in her life. The actress has taken on difficult characters in the past, like in last year's The Impossible, but said of her new role: “Playing Princess Diana was the hardest thing I've done. I wanted to try to embody her and get the essence of her."

Diana hits theaters on October 10.