A fictionalized portrayal of the rise of Catherine the Great from being an outsider to becoming the longest-reigning female ruler in Russia's history after she married Emperor Peter III.
In the second season, after learning that Catherine is pregnant, she and her husband Peter become further at odds. Catherine chooses to handle things independently in Russia, while Peter attempts to reclaim his powers again.
In Season 3, Katherine and Peter try to make their marriage work after several difficult challenges. Moreover, Katherine begins to make a name for herself in being a leader by achieving new accomplishments.