Elizaveta Vorontsova

Elizaveta Romanovna Vorontsova (Russian: Елизавета Романовна Воронцова) (13 August 1739 – 2 February 1792) was a mistress of Emperor Peter III of Russia. During their affair, Peter was rumored to have intentions of divorcing his wife Catherine (the future empress) to marry Vorontsova.
She belonged to the celebrated Vorontsov family that reached the pinnacle of power during the last years of the reign of Empress Elizabeth, when her uncle, Mikhail Illarionovich, served as Imperial Chancellor. Her father, General Roman Vorontsov, governed the provinces of Vladimir, Penza, Tambov, and Kostroma, where his name became a byword for graft and inefficiency.
Following her mother's death in 1750, the 11-year-old Elizaveta was attached to the Oranienbaum court of Grand Duke Peter's wife, Grand Duchess Catherine Alekseyevna (at this time, Peter was the heir to the throne). By accounts, Elizaveta was a slob: She "swore like a soldier, squinted her eyes, smelled bad, and spit while talking". Baron de Breteuil compared her appearance to that of a "scullery maid of the lowliest kind". Catherine herself would write of her as "very ugly, extremely dirty child with an olive skin". Peter, however, developed a fondness for her, which the court was at a loss to explain. Catherine called Elizaveta a "new Madame de Pompadour" (of whom she greatly disapproved), while the Grand Duke took to calling her "my Romanova" (a pun on her patronymic, Romanovna: his own surname was Romanov).
After Elizaveta's lover became Emperor in January 1762, he invested her with the Order of Saint Catherine and had rooms prepared for her in the newly built Winter Palace next to his own. She accompanied Peter in all his excursions and adventures, and foreign ambassadors reported to their governments that the Emperor was intending to banish his wife to a convent in order to marry Vorontsova. Some claim these rumors were what drove Catherine to join efforts with Vorontsova's own sister, Princess Ekaterina Dashkova, and staged a palace coup which removed her husband from power in July 1762. Controversy endures to the present day as to whether Catherine took any part in ... [Peter's] death shortly thereafter. However, Catherine's actions have been described as follows: "As for her husband, Catherine threw him in jail, and though she couldn't help show some sympathy—allowing him his own bed from home, along with his dogs, violin and even his personal doctor—she refused his most heartfelt and repeated request: She made sure that Peter and his mistress never saw each other again.

Catherine II, in her memoirs, pulled no punches when discussing Vorontsova. In a letter from June 1762, she claimed that the Vorontsovs had made plans to shut her up in a cloister and put their relative on the throne. Although Vorontsova wished to follow her lover into exile in Holstein (his homeland), his sudden death put an end to this prospect.
The Empress arranged her rival's marriage to an army colonel of humble background, and ordered them to withdraw to the countryside, where Vorontsova spent the rest of her days in bitterness and ill health, while her brothers Alexander and Semyon made spectacular careers in the diplomatic service.