In 1801 Count Nicholas Sheremetev, aged 50 and the richest man in Russia, secretly married 32-year-old Praskovia Kovalyova in a ceremony that shocked the Tsar and all of the nation's aristocrats.
Until just days before, Praskovia had been not only a peasant without any noble connections but a serf, a slave owned body and soul by the count himself. But she was no ordinary slave and their love story is one of the great romances of its time.
It is more than that, too. It is one of those tales that, in the wrong hands, could be one long purple passage but in the hands of a proper historian, who understands the social and political context of the reigns of Catherine the Great, Paul and Alexander, it serves as a brilliant window into the life of the richest and poorest inhabitants of imperial Russia - and much more besides.
As well as a love story, Douglas Smith has produced a revelatory history of Russian society, encompassing drunken peasant life and that little-known but compelling subject, Russian serf theatre.
Nicholas was the grandson of Peter the Great's chief commander, Field Marshal Count Boris Sheremetev, on whom the emperor bestowed colossal estates and many thousands of serfs. The Sheremetevs' wealth was massive even by the standards of Russia's plutocrats.
In 1795 the Russian population was 37 million, of whom the vast majority were serfs, owned by a mere 360,000 male nobles. Yet many of these nobles were relatively poor - the average aristocrat owned just 60 serfs and only 11 per cent owned more than 1,000 serfs. Nicholas Sheremetev, however, owned 210,000 serfs and estates in 17 provinces totalling more than two million acres (the family had 1,000 domestics working in their main residences).
Nicholas's father, Peter, inherited the field marshal's stupendous wealth, but henceforth the family scions abandoned the line of Petrine service in army and bureaucracy and tried to avoid court duties, although Peter was great friends with Catherine the Great and Prince Potemkin, her partner in power and love.
Peter Sheremetev founded a serf theatre on his estates that became famous for its quality. The serf theatres of the highest aristocracy, along with their serf orchestras and serf actresses, dancers and singers, were a peculiarity of Russia in the 'Golden Age of Nobility'.
Between 1770 and 1820, more than 2,000 of these slave-artists performed in more than 170 noble theatres and were bought and sold wholesale while at the same time becoming stars. For example, Prince Potemkin bought the whole serf orchestra of Count Kyril Razumovsky for 40,000 roubles.
The Sheremetev theatre was one of the wonders of the era: when the Holy Roman Emperor, Joseph II, visited Russia in 1781, Potemkin brought him to see the show. But Peter Sheremetev's love for theatre was nothing compared with the obsession it became for his son, Nicholas.
After his father's death in 1788, he spent even more on his theatre. Meanwhile, despite being the richest man in Russia, he avoided marriage. Brought up as a companion for Catherine's pug-nosed and bitter son, Grand Duke Paul, he lived a life of considerable debauchery before falling in love with his star singer and actress, Praskovia, whose stage name was 'the Pearl'.
They had met in about 1786 and notwithstanding her status, Nicholas's love for Praskovia was passionate, respectful and serious: 'I observed the character and qualities of my heart's desire and found in her a mind adorned with virtue, sincerity, a true love of humanity, constancy and faith in God.' Many nobles kept serf mistresses, especially beautiful actresses, but this love story was different. Nicholas and Praskovia lived together.
After Catherine's death, Emperor Paul appointed Nicholas Chief Marshal of the Court, a role that Nicholas hated. The emperor turned out to be a mad tyrant, Nicholas's health declined and he feared telling Paul, a martinet stickler for etiquette, about his unacceptable live-in lover. But Sheremetev was lucky, because Paul was assassinated and his successor Alexander I was much more indulgent: Sheremetev secretly freed his love and then married her.