[3] Marie Louise Élisabeth and her younger twin sister Henriette were born at the Palace of Versailles on 14 August 1727 to King Louis XV of France and his wife, Queen Maria Leszczyńska.

This engagement followed a tradition dating back to 1559 of cementing military and political alliances between the Catholic powers of France and Spain with royal marriages.

[3] Barrister Barbier wrote in his diary "It seems extraordinary that the eldest Daughter of France is not marrying a crowned head",[3] and d'Argenson speculated that the marriage was arranged only because of a plan to make Don Philip king of Naples and Sicily.

According to the memoirs of the Duke of Luynes, Elisabeth spend a great deal of time with her loving mother, Queen Marie Leszczyńska in her apartments prior to her departure.

When she left for Spain in September, Her mother wept alongside her younger siblings while the King was reportedly so moved that he entered her carriage and accompanied her for the first miles on her journey.

"[3] Élisabeth was described as "keen, ambitious and enterprising, untiring in her energies and passionately fond of her changing Europe to the advantage of her House, of imbuing everyone with a love for France and of making her son a prince worthy of his great French forefathers".

In the Treaty of Aix-la-Chapelle (1748) which ended the War of the Austrian Succession, Empress Maria Theresa ceded the duchies of Parma, Piacenza and Guastalla to Ferdinand VI of Spain.

She arrived in Versailles on the 11 December 1748 with a retinue composed of her camarera mayor the Marquise de Lcyde, her secretary of state the Duke of Montellano as major domo-in-chief, and three maids-of-honour.

[3] A courtier described Élisabeth as "charming" with "piercing eyes" that "express(ed) intelligence" while another, less sympathetic observer claimed she looked like a "well-endowed young woman, matured by motherhood".

[3] When she left Versailles on 18 October 1749, she brought a French retinue of followers, a trousseau and so many gowns that D’Argenson commented that her journey had cost the State twelve hundred thousand livres.

[6] Before the former duke, Philip's brother Charles, had left to become king of Naples, he had reportedly stripped the palace of much of its interior decoration and furniture, and the residence also lacked a garden.

[3] As duchess of Parma, Élisabeth was actively involved in state affairs; Philip never negotiated any business without consulting her, and she in turn never made a decision without considering the view of France and her French advisers.

[3] In 1750, Élisabeth's lady-in-waiting Madame de Leydc was rumored to have poisoned France's Chief Minister[clarification needed] at Parma, supposedly for being French.

Upon her return, she appointed Guillaume du Tillot as chief minister and administrator of the principality, securing both her own pro-French policy as well as marking France's de facto conquest of Parma.

[3] In the treaty, it had been suggested that Austria would cede the Austrian Netherlands as a kingdom for Philip, which would be even more favourable for France than to have Parma as a vassal, a plan which was supported by both Élisabeth and Louis XV.

During this time, Élisabeth also appointed the philosopher Étienne Bonnot de Condillac as her son's tutor despite opposition from the Jesuits, and arranged the marriage of her daughter Isabella to the Archduke Joseph of Austria, which took place in 1760.