The Turks declare war and Catherine recalls Alexi Orlov to Council. Zubov is used to spy on her. Grigory is ailing from a virus he caught in Crimea. She tries to keep her grandson Alexander from his parents and grooms him to succeed her. While Grigory is back in Crimea, he dies. Catherine is grief stricken and she dies as well. It is discovered that she married Grigory 10 years ago. Paul succeeds her.
Prince Paul's wife and child die in childbirth. Catherine forces him to remarry and it produces a boy. Grigory wants to take Crimea and Catherine does not want a war. Their relationship is becoming strained, so she sends him to the Crimea to negotiate the expansion of Russia. She makes Grigory a Prince to the anger of her son and cabinet ministers. She forces them all to resign and sends her son Paul to Austria on a diplomatic tour. She is cleaning house to make way for her lover.
Oscar-winner Helen Mirren will lead miniseries Catherine the Great as the tumultuous monarch and politician who ruled the Russian empire and transformed its place in the world in the 18th century.