Who dated Peter III of Russia?

Peter III Fyodorovich (Russian: Пётр III Фёдорович, romanized: Pyotr III Fyodorovich, born Charles Peter Ulrich of Schleswig-Holstein-Gottorp; 21 February 1728 – 17 July 1762) was Emperor of Russia from 5 January 1762 until 9 July of the same year, when his wife, Catherine II "the Great", overthrew him in a palace coup d'état. He implemented many notable reforms during his reign, though he is criticised for undoing Russian gains in the Seven Years' War by forming an alliance with Prussia.

Peter was the son of Duke Charles Frederick of Holstein-Gottorp, and Grand Duchess Anna Petrovna of Russia, the latter of whom died of puerperal fever after childbirth. After his succession to the throne of Holstein-Gottorp on the event of his father's death, Peter was made heir presumptive to both the Russian and Swedish thrones in 1742. Due to his conversion to Russian Orthodoxy, he was disqualified from becoming King of Sweden.

Peter married his paternal second cousin, Princess Sophie of Anhalt-Zerbst, who took the Orthodox name of Catherine Alexeievna, in 1745. They had one child who survived to adulthood, Paul Petrovich. Peter succeeded his maternal aunt as Emperor of Russia in 1762. After a 186-day reign, Peter III was overthrown by his wife, and soon died under unclear circumstances. The official cause proposed by Catherine's new government was that he died due to hemorrhoids. This explanation was met with skepticism, both in Russia and abroad, with notable critics such as Voltaire and d'Alembert expressing doubt about the plausibility of death from such a condition.

After Peter III's death, many impostors thrived, pretending to be him, the most famous of whom were Yemelyan Pugachev and the "Montenegerin Tsar Peter III" (Stephan the Little).

Marie Anne de Coislin (1732-1817), was a French aristocrat, known as the mistress to Louis XV of France in 1755. She was the king's Petite maîtresse (unofficial mistress), not his Maîtresse-en-titre (official mistress).

She was the daughter of the marquis Louis de Mailly (1696-1767) and the lady-in-waiting Anne Françoise Elisabeth Arbaleste de Melun and married in 1750 to the duke Charles Georges René du Cambout de Coislin (d. 1771), but they separated early on and she moved back with her parents.

In 1755, Louis François, Prince of Conti launched her as his candidate to replace Madame de Pompadour as official mistress of the king. She was the first serious candidate to be put up against Madame de Pompadour since Charlotte Rosalie de Choiseul-Beaupré, and she was also to be the last. She did succeed to be the secret lover of the king, which attracted some attention at court. She became known as l'altière Vasthi. Ultimately, however, the plot failed, and she was ousted from court by Madame de Pompadour. After this, there was no more serious rival to replace Madame de Pompadour, and the king mainly settled with his unofficial lovers at the Parc-aux-Cerfs.

Marie Anne de Coislin had affairs with the Prince de Conti and the count de Coigny, and was claimed to have had affairs with Christian VI of Denmark, Gustav III of Sweden and Peter III of Russia. It is unknown if these rumours where true, but Christian VI and Gustav III did visit her during their visits to Paris, which attracted attention at the time.

She did not leave France during the French Revolution, but lived as a servant in Rouen, Brittany and Vendée during the Reign of Terror. After the fall of Robespierre, she resumed her former life and property. She remarried in 1793 to Louis-Marie duc de Mailly (d. 1795).

Countess Elizaveta Romanovna Vorontsova (Russian: Елизавета Романовна Воронцова; 13 August 1739 – 2 February 1792) was a Russian noblewoman and lady-in-waiting. She was a mistress of Emperor Peter III of Russia (reigned February to July 1762). During their affair, rumors suggested that Peter had intentions of divorcing his wife Catherine (the future empress) in order to marry Vorontsova.