The reign of Russia’s Catherine the Great was the longest the country had ever seen, but the empress was not Russian by birth. She was born Sophie von Anhalt-Zerbst, the daughter of a Prussian prince. When she was fifteen she married Peter III, grandson of Peter the Great and heir to the Russian throne. Catherine wholly embraced her new identity, learning Russian and converting to the Russian Orthodox religion.

But her marriage was a failure: Peter was an alcoholic who showed little interest in his wife, preferring to hole up in his room and play with toy soldiers. The couple had trouble consummating their marriage, though, after seven years, they eventually did. Around that time, Catherine began her love affairs; her need for love was as great as her ambition. Peter eventually became king, but his six-month rule proved disastrous, and in 1762, Catherine participated in a military coup to unseat him and claim his throne for herself.

As empress, she significantly extended Russia’s borders, revamped its educational system, and cultivated a glittering court on par with its European counterparts. Intellectually curious and viewing herself as an enlightened ruler, she actively corresponded with Voltaire and Diderot. But she failed to carry out her plan to free Russia’s serfs, leaving them worse off than before—her enlightenment had its limits.