The daughter of Stanislaus I Leszczyński, the deposed King of Poland, and Catherine Opalińska, her 42-years and 9 months service was the longest of any queen in French history.

A devout Catholic throughout her life, Marie was popular among the French people for her numerous charitable works and introduced many Polish customs to the royal court at Versailles.

She was born in Trzebnica in Lower Silesia, the year before her father was made King of Poland by Charles XII of Sweden, who had invaded the country in 1704.

[3] During the escape, Marie was separated from the rest of her family; she was later found with her nurse hiding in a crib in a stable, although another version claims it was actually a cave in an old mineshaft.

[3] In Sweden, the family was welcomed by the queen dowager Hedwig Eleonora of Holstein-Gottorp and became popular members of society life on the estates of the nobility around Kristianstad.

[5] While her mother Catherine and grandmother Anna Leszczyńska reportedly suffered from a certain degree of bitterness over their exile and loss of position which worsened their relationship with Stanislaus, whom they occasionally blamed for their exile, Marie was close to her father and spent a lot of time conversing with him, though she was evidently of a different nature as she "possessed the gift of suffering in silence and of never wearying others with her troubles" and was said to have developed "a profound and intense piety", which gave "to her youthful mind the maturity of a woman who no longer demands happiness".

[4] In 1724, Count d'Argensson proposed she marry the new Duke of Orléans, but her intended mother-in-law Françoise Marie de Bourbon wished for a dynastic match with political advantage.

Anne and Amelia of Great Britain, who were considered with the understanding that they would convert to the Catholic faith upon marriage, were favored by the Duke of Bourbon and Madame de Prie because they were supported by their political financiers, the firm of Paris Brothers.

Marie's father Stanislaus had been a monarch for only a short time and she was thought to be a poor choice and of inferior status, not worthy of being queen of France.

The nobility and the court looked upon the future queen as an upstart intruder, the ministers as a cause to diplomatic trouble with Spain and Russia, whose princesses had been refused in favor of Marie, and the general public was also reportedly initially dissatisfied with the fact that France would gain "from this marriage neither glory nor honor, riches nor alliances.

She was escorted by Mademoiselle de Clermont, seven ladies-in-waiting, two maids-of-honour, numerous equerries and pages in a long train of coaches; however, she was not welcomed by triumphal entries, diplomatic greetings or the other official celebrations, as was normally the custom upon the arrival of a foreign princess for a royal marriage.

The Duke de Richelieu, best friend of the King, noted in his memoirs that Louis XV had a "true passion" for Marie Leczinska and at first resisted the idea on taking a mistress while his wife was always pregnant.

His first minister, Cardinal Fleury, however, was displeased and decided that until the Queen had given birth to a son she could not be allowed to accompany the King on his trips but had to stay at Versailles.

The long-awaited dauphin, Louis, was born on 4 September 1729 to the relief of a country whose royal family had had a history of failing to establish a secure male line of succession.

Queen Marie never managed to develop political influence and instead focused on numerous charitable activities such giving money, edible foods, medicines as well as sewing and making clothes to the poor which was appreciated by ordinary Frenchmen.

The doors were locked to ensure secrecy and the Duke presented the King with a report from their ambassador in Rome which blamed Fleury for the French failure in a dispute with the Pope.

Cardinal Fleury warned the King that no woman should be allowed to participate in state affairs and that listening to women's advice would lead to disaster.

[5] The day following the fall of the Duke de Bourbon's ministry, Louis XV stated to Queen Marie that he demanded of her to let herself be directed by Cardinal Fleury in the future with the words: Marie's attempt to participate in state affairs during the events of 1726 resulted in a crisis in her relationship with Louis XV, and she sought advice on how to behave from the Princess of Carignano, who, unbeknownst to her, was a spy in service of Savoy.

[4] The princess' advice was that as Queen of France, it was Marie's duty not to become involved in political intrigues and plots, but to act as an example of virtue and piety; a role model of a "Catholic consort of the Most Christian King".

[4] After the 1726 crisis and until the birth of a dauphin in 1729, Cardinal Fleury and the Princess of Carignano made long running preparations to replace Marie if she should die in childbirth, preferably with Charlotte of Hesse-Rheinfels-Rotenburg.

[4] Her political activity after 1726 was limited to asking Louis XV to grant a pension or a promotion to a friend, and she often used Cardinal Fleury as a mediator to achieve this.

She valued the ritualized pomp and court presentations in order to increase her dignity and win the respect of the court nobility, which was necessary because she had no prestigious dynastic connections of birth and was thus initially seen as low born by them:[4] her successor as queen, Marie Antoinette, was to ignore many of these rules, and once pointed out, that in contrast to her predecessor Queen Marie Leszczyńska, it was not necessary for her to enhance her status and dignity since her dynastic status was evident by birth, and that she could therefore afford to relax on her etiquette without losing respect.

Marie's private circle of friends was completed with the addition of President Hénault (her Surintendant since 1753) and Comte d'Argenson, whom she had asked not to address her with her title and with whom she also consulted when she wished to have a pension or a promotion given to a protégé.

[4] Like her mother, Marie maintained a political correspondence with Margareta Gyllenstierna, the spouse of Arvid Horn, after she had made her acquaintance during her stay in Sweden.

[9] When her first daughter-in-law died in 1746, the Queen, very fond and loving of her only son, opposed the selection of his next spouse, the Duchess Marie-Josèphe of Saxony, because she was the daughter of her father's rival, King Augustus III of Poland.

In the culinary side, Marie made eating lentils popular in France and was also noted for inventing along with her chefs the now famous French meat pastry called "bouchée à la reine" in 1735.

Furthermore, President Henault and de Luynes noted that Queen Marie was fluent in seven languages such as Italian, German, French, Latin, Swedish, and English aside from her native Polish and was very useful when receiving foreign ambassadors.

Louis XV's wife was a great lover of music as she played the hurdy gurdy, harpsichord and guitar and was an avid engraver and painter.

Marie was also skilled in embroidery and needlework wherein she gave her creations to poor churches and was the promoter of many other artists such as Alexis-Simon Belle, Piere Gobert, Jean Louis Tocque, Charles Van Loo, Maurice Quentin de Latour Hyacinth Rigaud and the poet Moncrift.

Duke de Luynes stated in his memoirs that it was Marie who originally introduce the porcelain flowers to courtiers in Versailles by displaying it in her apartments in April 1748 after having it commissioned from Sèvres.