the Emperor's cousin
Princesse Mathilde was the daughter of Jérome Bonaparte by his second marriage to Catharina von Württemberg. She was therefore the sister of 'Plon-Plon,' and a first cousin of Napoléon III.
Born in 1820 at Trieste, and raised in Florence and Rome, she was at one time engaged to her cousin, the future Emperor. However, in 1840 she married the wealthy Russian Prince Demidov, who treated her so badly, insulting her and striking her in public, that in 1847 Tsar Nicholas I finally ordered him to live apart from his wife and pay her a handsome allowance.
Under the Second Empire, Princesse Mathilde held a well-reputed literary and artistic salon, while maintaining ties with the Imperial court in St Petersburg. After the death of her first husband in 1870, she married Claudius Marcel Popelin in 1873. He second husband was an erudite artist, enameller, bibliophile and poet.
At the beginning of the 20th century, the Princesse, holding semi-royal court in her Paris mansion, remarked of her uncle Napoléon I to Marcel Proust: 'If it weren't for him, I'd be selling oranges in the streets of Ajaccio.' It's an amusing comment on her family's relatively humble origins, but in actual fact she is more likely to have been the wife of a reasonably prosperous solicitor.
She died in Paris in 1904 at the age of 75.