After months of anticipation and speculation, the lead roles for the film adaptation of 50 Shades of Grey have finally been announced.

Dakota Johnson, of the short-lived FOX sitcom "Ben and Kate" will star as Anastasia "Ana" Steele. Charlie Hunnam of FX's "Sons of Anarchy" will be playing the role of Christian Grey.

E.L. James', the author of Fifty Shades of Grey and its sequels, made the announcement through a series of tweets on Twitter.

"I am delighted to let you know that the lovely Dakota Johnson has agreed to be our Anastasia in the film adaptation of Fifty Shades of Grey," James wrote in her first tweet announcing the film's cast.

A few moments later, James made broke the news about Christian Grey's character. "The gorgeous and talented Charlie Hunnam will be Christian Grey in the film adaptation of Fifty Shades of Grey," James wrote via Twitter.

Shortly after James' tweets, Distributor Focus Features confirmed the castings.

James' tweets were the first real casting announcements made about the film. Fifty Shades of Grey will be released Aug. 1, 2014.

James made sure her fans were prepared for the long-awaited news she was about to release. "Good morning all," James wrote via Twitter earlier that same Monday. "Hold on to your hats..."

Sam Taylor-Johnson will direct Fifty Shades of Grey. Meanwhile, James, Michael de Luca and Dana Brunetti will produce.

Johnson, 23, is also known for her small role in The Social Network. De Luca and Brunetti also served as producers for the film. Following The Social Network, Johnson made appearances in 21 Jump Street,The Five-Year Engagement and Need for Speed. She is currently filming an adaptation of Cymbeline.

Hunnam, 33, is an England native and also appeared in "Queer as Folk" and "Undeclared."

James' tweets eliminate rumors that other stars would be casted as the leads. For example, Shailene Woodley, Analeigh Tiptop and Emma Watson were highly-rumored to be the next Anastasia Steele. Meanwhile, Ian Somerhalder, Henry Cavill and Armie Hammer were amongst the names speculated to portray Christian Grey.

Fifty Shades of Grey and its sequels, Fifty Shades Darker and Fifty Shades Freed, have sold over 70 million copies and been translated into 50 languages.