As Mme d'Étiolles became known in society, the King came to hear of her. In 1745, a group of courtiers, including her father-in-law, promoted her acquaintance with the monarch, who was still mourning the death of his second official mistress, the duchesse de Châteauroux.
Jeanne Antoinette was invited to a royal masked ball at the Palace of Versailles on the night of 25 to 26 February 1745, one of the many fêtes given to celebrate the marriage of the Dauphin Louis de France (1729–1765) to the Infanta Maria Teresa of Spain (1726–1746). By March, she was the King's mistress, installed at Versailles in an apartment directly below his. On 7 May, the official separation between her and her husband was pronounced.
To be presented at court, she required a title. The King purchased the marquisate of Pompadour on 24 June and gave the estate, with title and coat-of-arms, to Jeanne Antoinette, making her a Marquise. On 14 September, she was formally introduced to the court by the king's cousin, the Princess de Conti. She quickly mastered the highly-mannered court etiquette. Her mother died on Christmas Day of the same year, and did not live to see her daughter's achievement at becoming the undisputed royal mistress.
The Marquise de Pompadour never had much direct political influence, but supported the Maréchal de Belle-Isle and endorsed the duc de Choiseul to the king. However, she did wield considerable power and control behind the scenes, which was highlighted when another of the king's mistresses, Marie-Louise O'Murphy de Boisfaily, "la belle Morphyse", attempted to replace her around 1754. In 1755, the younger and less experienced Morphyse was married off to an Auvergne nobleman, Jacques de Beaufranchet, seigneur d'Ayat (Lord of Ayat) and uncle of the illustrious General Louis Desaix, who fought during the French Revolution under General Napoleon Bonaparte. Their son (1757–1812), Louis Charles Antoine de Beaufranchet, a maréchal de camp, was present at the execution of Louis XVI.
The Marquise de Pompadour had many enemies among the royal courtiers, who felt it a disgrace that the king would thus compromise himself with a commoner. She was very sensitive to the unending libels called poissonnades, a pun on her family name, Poisson, which means "fish" in French. Only with great reluctance did Louis take punitive action against known enemies such as the duc de Richelieu.
Her importance was such that she was even approached in 1755 by Wenzel Anton Graf Kaunitz, a prominent Austrian diplomat, asking her to intervene in the negotiations which led to the 1756 Treaty of Versailles.[citation needed] This was the beginning of the Diplomatic Revolution, which saw France allied to her former enemy Austria.
Under these changed alliances, the European powers entered the Seven Years' War, which saw France, Austria, and Russia pitted against Britain and Prussia. France suffered a defeat at the hands of the Prussians in the Battle of Rossbach, in 1757, and eventually lost her American colonies to the British. After Rossbach, Madame de Pompadour is alleged to have comforted the king saying this now famous by-word: "au reste, après nous, le Déluge" ("After us, the Deluge")[citation needed]. France emerged from the war diminished and virtually bankrupt.
However, Mme de Pompadour persisted in her support of these policies, and when Cardinal de Bernis failed her, she brought Choiseul into office and supported him in all his great plans: the Pacte de Famille, the suppression of the Jesuits and the Treaty of Paris (1763) sealing the loss of Canada. Britain's victories in the war had allowed it to surpass France as the leading colonial power—something which was commonly blamed on Pompadour.
There were several reasons for the Marquise de Pompadour’s lasting influence over Louis that distinguished her from past mistresses. First, she decidedly established a cordial relationship with Marie Leszczyńska. The Queen had been snubbed by the king’s previous mistresses but Pompadour realized that showing respect for Marie eased Louis' guilt and allowed him to have a strong relationship with his children. The Queen often said " If there must be a mistress, better her than any other. " She also put all of her effort into bringing fun into the melancholy life of the King. Unlike the other females in the King's life the Marquise de Pompadour accompanied him while hunting, playing cards, and touring properties. She also threw dinner parties for him and put on plays that exalted him. Lastly, the royal mistress continuously reminded Louis of her beauty by frequently commissioning paintings, mostly by Francois Boucher, that highlighted her exquisite features and hid her aging looks.
The Marquise de Pompadour was an accomplished woman with a good eye for Rococo interiors. She was responsible for the developme