Diane Keaton is headed to HBO. The Hollywood Reporter has learned that the Oscar winner has signed on to star opposite Jude Law in the upcoming series The Young Pope. The eight-part project centers on a fictional American pope, Pius XIII, played by Law, born Lenny Belardo, who becomes the most conservative leader the Catholic Church has ever seen. The Young Pope is the first-ever TV series from Italian filmmaker Paolo Sorrentino. The Young Pope is being produced by Wildside and co-produced by Haut et Court TV.