Diane Keaton is set to star opposite Jude Law in Paolo Sorrentino-directed series The Young Pope, a joint production of HBO, Sky and Canal +.

Filming begins this week on the eight-episode series, which tells the fictional story of the beginning of the Pontificate of Pius XIII (Law), born Lenny Belardo. He is a man of great power who’s stubbornly resistant to the Vatican courtiers, unconcerned with the implications for his authority. Keaton plays Sister Mary, a nun from the U.S. now living in Vatican City. She raised Lenny, taught him to live right by God and helped him get to the papacy. She continues to have power over him and used him to get her new position in the Vatican. Sorrentino will direct all eight episodes.

Oscar winner Keaton previously toplined the HBO comedy pilot Tilda and will next be seen in the feature Love the Coopers.

The Young Pope is produced by Wildside, and co-produced by Haut et Court TV and MediaPro. Lorenzo Mieli and Mario Gianani executive produce for Wildside with John Lyons. Caroline Benjo, Carole Scotta and Simon Arnal executive produce for Haut et Court TV.