A diplomatic agreement signed between Austria and France at the Palace of Versailles on May 1, 1757, during the Seven Years' War expands on the First Treaty of Versailles from the previous year that had established the Franco-Austrian Alliance.

Under the terms of the new agreement, commonly known as the Second Treaty of Versailles, France agrees to assist Austria in regaining the province of Silesia from Prussia in exchange for Austria's cession of the Austrian Netherlands to France at the war's conclusion—the acquisition of which has long been a goal of the French state.

Financial subsidies paid from France to Austria are continued.

This confirms British fears of the depth of the alliance.

In the wake of the treaty, ...

...French troops move to occupy key ports and settlements in the Austrian Netherlands such as Ostende and ...

...Nieuport—freeing up their Austrian garrisons to move east to attack Prussia.

This particularly alarms the British, who have long sought to prevent the French moving into the Low Countries.

The Treaty thus brings to an end the barrier that had existed for forty years.

The French intend to place on the throne of a new puppet state in the Southern Netherlands a Bourbon monarch from the Spanish branch of the dynasty, Duke Philip of Parma.

The treaty also serves to confirm a planned partition of Prussia that is to take place between Russia, Sweden and Saxony.

The year 1758 has been a disappointment to France, and in the wake of this Étienne François, duc de Choiseul, is appointed to supplant Cardinal de Bernis as minister for foreign affairs, so largely has the direction of French foreign and military policy during the Seven Years' War.

Choiseul plans to end the war in 1759 by making strong attacks on Britain and Hanover.

The eldest son of François Joseph de Choiseul, marquis de Stainville (1700–1770), Étienne François was born in Nancy in the Duchy of Lorraine where his father was one of the leading advisors to the Duke of Lorraine.

At birth, he bore the title of comte de Stainville.

Duke Francis Stephen of Lorraine (now the Holy Roman Emperor Francis I) had been pressured in 1737 into giving up Lorraine and becoming ruler of Tuscany in Italy.

Étienne François, realizing that continued loyalty to the House of Lorraine would limit his opportunities, had transferred his allegiance to France.

After gaining experience during the Austro-Turkish War, the comte de Stainville had entered the French army, and during the War of the Austrian Succession had served in Bohemia (1741) and in Italy (1744), where he distinguished himself at the Battle of Coni.

He was also present at the Battle of Dettingen in Germany and carried news of the French defeat there to Paris.

He had been appalled by what he had witnessed of the French forces at Dettingen, and his experiences will motivate his later reforms of the French military.

With the army in the Low Countries from 1745 to 1748,  he had been was present at the sieges of Mons, Charleroi and Maastricht.

He attained the rank of lieutenant-general and, in 1750, married Louise Honorine Crozat, daughter of Louis François Crozat, marquis du Châtel (d. 1750), who brought her husband her share of the large fortune of her grandfather Antoine Crozat and has proved a most devoted wife.

Choiseul had gained the favor of Madame de Pompadour by procuring for her letters that King Louis XV had written to his cousin's wife, Charlotte-Rosalie de Romanet, comtesse de Choiseul-Baupré, with whom the king had formerly had an intrigue; and after a short time as bailli of the Vosges he had been given the appointment of ambassador to Rome in 1753, where he was entrusted with the negotiations concerning the disturbances called forth by the papal bull Unigenitus.

He acquitted himself skillfully in this task, and, in 1757, his patroness had obtained his transfer to Vienna, where he was instructed to cement the new alliance between France and Austria.

He had been one of the principal authors of the Second Treaty of Versailles, signed in May 1757, which pledged the two states to a combined war in Germany against Prussia.

Ferdinand VI of Spain at the end of 1758 was displaying the same symptoms of depression that his father used to suffer from.

Ferdinand had lost his devoted wife, Infanta Barbara of Portugal, in August 1758 and had fallen into deep mourning for her.

He named his half-brother Charles, Duke of Parma and Piacenza, his heir presumptive on December 10, 1758 before leaving Madrid to stay at Villaviciosa de Odón, where he died on August 10, 1759.

At that point, Charles had been proclaimed King of Spain under the name of Charles III of Spain, respecting the third Treaty of Vienna, which states he will not be able to join the Neapolitan and Sicilian territories to the Spanish throne.

He is later given the title of Lord of the Two Sicilies.

The Treaty of Aix-la-Chapelle, which Charles has not ratified, foresees the eventuality of his accession to Spain; thus Naples and Sicily go to his brother Philip, Duke of Parma, while the possessions of the latter are divided between Maria Theresa (Parma and Guastalla) and the King of Sardinia (Plaisance).

Determined to maintain the hold of his descendants on the court of Naples, Charles had undertaken lengthy diplomatic negotiations with Maria Theresa, and in 1758 the two had signed the Fourth Treaty of Versailles, by which Austria formally renounced the Italian Duchies.

Charles Emmanuel III of Sardinia, however continued to pressure on the possible gain of Plaisance and even threatened to occupy it.

In order to defend the Duchy of Parma from Charles Emmanuel's threats, Charles deployed troops on the borders of the Papal States.

Thanks to the mediation of Louis XV, Charles Emmanuel renouncea his claims to Plaisance in exchange for financial compensation.

Charles thus assures the succession of one of his sons and, at the same time, reduces Charles Emmanuel's ambitions.

The eldest son of Charles, Infante Philip, Duke of Calabria, has learning difficulties and is thus taken out of the line of succession to any throne; he will die in 1777 in Portici where he had been born in 1747.

The title of Prince of Asturias is given to Charles, the second-born.

The right of succession to Naples and Sicily is reserved for his third son, Ferdinand; he will stay in Italy while his father is in Spain.

Charles' formally abdicates the crowns of Naples and Sicily on October 6, 1759 in favor of Ferdinand.

Charles leaves his son's education and care to a regency council composed of eight members; this council will govern the kingdom until the young king is 16 years old.

Charles and his wife arrive in Barcelona on October 7, 1759.

Charles III of Spain represents a new type of ruler: the ruler who follows Enlightened absolutism.

This is a form of absolute monarchy or despotism in which rulers embrace the principles of the Enlightenment, especially its emphasis upon rationality, and apply them to their territories.

They tend to allow religious toleration, freedom of speech and the press, and the right to hold private property.

Most foster the arts, sciences, and education.

Charles shares these ideals with other monarchs, including Maria Theresa of Austria, her son Joseph, and Catherine II of Russia, (the Great).

The principles of the Enlightenment had been applied to his rule in Naples and he intends to do the same in Spain, though on a much larger scale.

Charles goes about his reform with the help of the Marquis of Esquilache, Count of Aranda, Count of Campomanes, Count of Floridablanca, Ricardo Wall and the Genoan aristocrat Jerónimo Grimaldi.

Thanks to these principles, the king decides to forbid bullfighting, a practice regarded by the king himself as brutal and uncivilized.

The first crisis that Charles has to deal with is the death of his beloved wife Maria Amalia, who dies unexpectedly at aged thirty-five on September 27, 1760, at the Palace of Buen Retiro on the eastern outskirts of Madrid.

She is buried at the El Escorial in the royal crypt.

A marriage is arranged between Princess Isabella of Parma and Archduke Joseph of Austria, heir to the Habsburg Monarchy, in 1760.

After a marriage by proxy, Isabella is escorted to Austria. 

At the age of eighteen, Isabella marries Joseph II on October 6, 1760, in a ceremony lasting for days. 

Joseph is thrilled with his new bride and overwhelms Isabella with his love.

In return, she increasingly locks herself away, so much so that shortly after their wedding, Isabella is plunged into melancholy.

Born Isabella Maria Luisa Antonietta Ferdinanda Giuseppina Saveria Dominica Giovanna at Buen Retiro Palace in Madrid, she is an Infanta of Spain and has grown up at the court of her grandfather, Philip V of Spain.

Her father is the Spanish Prince Philip, who is Duke of Parma in Italy.

Her mother was the fourteen-year-old Elisabeth of France, the eldest daughter of Louis XV of France.

Isabella's parents' marriage had not been happy, and for nearly ten years Isabella had remained an only child.

Isabella had been very close to her mother and was distraught when she died of smallpox in 1759.

Henceforth, Isabella has been convinced she, too, will die young.