Helen Mirren stars as Catherine the Great, as the brilliant monarch who ruled the Russian empire and transformed its place in the world in the eighteenth century. This limited series charts Catherine's tumultuous reign as the cunning and ambitious empress fights off threats to her crown, wages war with the Ottoman Empire and expands Russia's borders as far as the Black Sea and Crimea. It also chronicles the passionate love affair between Catherine and Russian military leader Grigory Potemkin.