Casting Natalie Portman and Scarlett Johansson as rival sisters in the historical romance “The Other Boleyn Girl” was surely a moment of inspiration.

Even more so as the two young actresses undertook unexpected roles: the serene and soft-spoken Portman portrayed ambitious and unscrupulous Anne Boleyn while Johansson gave life to the meek and victimized Mary Boleyn. The film’s other star, Eric Bana, imbues the confused and adulterous King VIII of England with masculinity and handsomeness.

Its stellar cast and a script based on a best-selling novel landed “The Other Boleyn Girl” at No. 4 on the North American box office, with an estimated $8.3 million in ticket sales, confirming studio anticipations.

“The Other Boleyn Girl” is based on the 2002 novel of the same title by British author Philippa Gregory. It has been adapted before, in the form of a short drama for BBC, with Natascha McElhone in one of the main roles.

The book was adapted by Peter Morgan, nominated for an Academy Award for writing “The Queen,” the 2006 film starring Helen Mirren. Director Justin Chadwick recently adapted Charles Dickens’ “Bleak House” for the BBC.

“The Other Boleyn Girl” premiered on Feb. 15 at the Berlin International Film Festival and opened in North American theaters Friday.

Critical reception was mixed, with review aggregator Rotten Tomatoes giving it an average rating of 5.2 out of 10, as of Monday, March 3. Consensus: “Though it features some extravagant and entertaining moments, ‘The Other Boleyn Girl’ feels more like a soap opera than historical drama.”

Rated PG-13 for mature thematic elements, sexual content and some violent images, the film’s story of love, betrayal, ambition, ruthless scheming and passionate plotting drew in mostly female crowds; women and girls made up nearly three quarters of the audience, with two-thirds of moviegoers aged 35 and under, the studio said.

Rory Bruer, Sony’s president of domestic distribution, was optimistic before the weekend: “We’re in for the long haul. It's a picture that we think will have a very high screen average and that will translate into a very good multiple.”

The film opened in less than 1,200 theaters but nevertheless ranked high on the charts with some $7,000 per theater.

The cast also includes Jim Sturgess (“Across the Universe”) and Kristin Scott Thomas. Academy Award-winning costume designer Sandy Powell was praised for her work on the rich ensembles worn by the characters, as was BAFTA Award winning production designer John-Paul Kelly.