Washington, Apr 19 : Harry Potter star Emma Watson is all set to star in a period film titled 'Napoleon and Betsy', to be directed by Benjamin Ross.

The 18-year-old star will be playing Betsy Balcombe, a young, rash noblewoman trapped on the isolated British Isle of St. Helena who falls in love with Napoleon, who is in exile on the island.

She will be stepping in the shoes of Scarlett Johansson, who stepped out of the film as the part went on to become a lot younger, reports the Hollywood Reporter.

However, the film would still be produced by Johansson, along with Alexandra Milchan, Melanie Sloan and Gilles Arondeau.

Watson is popular for her role as Hermione Granger in Warner Bros.' 'Harry Potter' films, and is right now working on the sixth instalment in the series, namely 'Harry Potter and the Half-Blood Prince'.

She will start shooting for 'Napoleon and Betsy' in fall 2009, when she completes the last flick in the Harry Potter series 'Harry Potter and the Deathly Hallows', which will go on the floors in early 2009.

ANI