Benedict Cumberbatch has joined the cast of 'Twelve Years a Slave'.

The 'Sherlock' star will star alongside Michael Fassbender and Brad Pitt in the movie which tells the real-life story of Solomon Northup, a black slave living in New York in the 1850s who is enticed to go on a trip to Washington only to end up being kidnapped and sold into slavery.

Benedict will play the plantation owner who buys Solomon (Chiwetel Ejiofor) and is won over by his engineering skills.

Solomon eventually won his freedom when a Canadian man smuggled letters to his wife to lead a court case which eventually saw him released.

Steve McQueen will direct the movie based on a script adapted from Northup's autobiography by British filmmaker Steve and John Ridley.

This will be the third time Fassbender - best known for the role of Magneto in 'X-Men: First Class' - will be working with Steve after appearing in 'Hunger' and sex addiction movie 'Shame'.

Benedict has recently been working on the 'Star Trek' sequel - which stars Chris Pine (James T. Kirk), Zachary Quinto (Spock) and Simon Pegg (Scotty) - scheduled to hit cinemas in May 2013.