David Tennant and Guy Pearce will soon be sharing the silver screen with Brooklyn star Saoirse Ronan.

Variety reports that both David Tennant and Guy Pearce have joined the cast of Working Title’s upcoming drama, Mary, Queen of Scots.

The upcoming biopic, which has already started filming in both England and Scotland, is based off of John Guy’s biography My Heart Is My Own: The Life of Mary Queen of Scots.

Set in the 16th century, the period drama will tell the story of when Mary Stuart (Ronan) became Queen of France at the young age of 16, only to be widowed two years later. From there, we’ll see her return to her homeland of Scotland, where she’ll reclaim the throne just as Scotland and England are set to fall under the rule of Queen Elizabeth I (Margot Robbie).

Though Tennant and Pearce have officially joined the cast, there’s no word yet on who they’ll be playing. Both actors join previously announced cast members Jack Lowden, Joe Alwyn, Martin Compton, and Downton Abbey alumn Brendan Coyle.

To celebrate the start of filming, Focus Features also released a first look photo of Ronan in the upcoming film. The new still features the Academy Award-nominated actress dressed in a sapphire gown, with her long red hair draped over one shoulder.

Check out the image below:

Directed by Josie Rourke with a screenplay by Beau Willimon, Mary, Queen of Scots is slated to premiere in theaters sometime in 2018.