Episode 4

S1 E4: Series finale. Following a declaration of war by the Ottomans, Catherine makes a weary Potemkin supreme commander of the armed forces and he's forced to fight once more for Catherine and Russia. An embittered Alexei and Paul plot to bring down the Empress by exploiting her new lover, the vain and power-hungry Platon Zubov. Catherine and Potemkin's failure to see eye to eye on how to respond to a joint ultimatum by Britain and Germany threatens the heart of their relationship. As her reign draws to an end, Catherine becomes increasingly paranoid and despotic, handing greater power to Zubov and setting out to change the line of succession.