Franka Potente will star in Constantin Film's big-screen version of Donna Cross' best-selling novel about a female pope,
Pope Joan, says the Hollywood Reporter.
The feature will see Potente play Johanna von Ingelheim, a 9th century woman of English extraction born in the German city of Mainz who disguises herself as a man and rises through the Vatican ranks.
The project is scheduled to begin shooting in May.