EXCLUSIVE: Eye In The Sky and Close To The Enemy actress Phoebe Fox has joined Elle Fanning and Nicholas Hoult in Hulu’s drama series pilot The Great.

Written and executive produced by Tony McNamara (The Favourite), the series charts the rise to power of Catherine the Great (Fanning) and her explosive relationship with husband Peter (Hoult), the emperor of Russia. Fox will play third lead Marial, Catherine’s right hand woman.

As we previously revealed, the project hails from MRC (House of Cards). Fanning is also executive producer with Marian Macgowan, Echo Lake and Thruline. Shoot is underway with Matt Shakman (Game Of Thrones) directing.

Catherine II, born Princess Sophie of Anhalt-Zerbst, was the daughter of a Prussian general, who was introduced to the prospective tsar Peter of Holstein-Gottorp when she was only 10 as part of European Royal families’ use of marriages as a tool for strengthening (and weakening) political ties between countries. Though she admitted to finding him detestable at first, the two eventually married after she had turned 16.

Their union was tumultuous, with both rumored to have extramarital affairs, and Peter’s temper becoming unbearable. Only six months into him ascending to the Russian throne, Catherine organized his opponents to overthrow him to start her successful 34-year rule. He was assassinated.

HBO and Sky have a Catherine the Great four-part series coming up about the Empress’ later years on the throne with Helen Mirren in the title role.

Stage and screen actress Fox will next be seen in Daniel Alfredson’s Intrigo: Samaria and in Sky One drama Curfew. She recently wrapped on Amazon’s The Aeronauts with Eddie Redmayne and Felicity Jones. She is repped by Curtis Brown and WME.