[2] Crillon joined the Régiment du Roi (King's Regiment) in 1734, aged 16, as a lieutenant en second and participated in France's Italian campaign during the War of the Polish Succession.

He was soon promoted to lieutenant en premier and took part in a number of notable actions, including the Battle of San Pietro, under the command of the Marshal de Villars.

Crillon won particular renown for his tenacious defence of Landau an der Isar against a 10,000–strong attacking force led by the Grand Duke of Tuscany.

[4] In May 1745, he fought in the major Battle of Fontenoy near Tournai in modern-day Belgium and captured nearly 50 pieces of artillery from the Dutch, British, and Hanoverian alliance opposing the French.

On 10 July, he fought in what the French termed the battle of the Mésle at Dendermonde near Ghent, leading 8,000 men to victory against a British, Austrian and Dutch force.

He took part in the 1747 campaign against the Republic of Genoa, serving in the Army of Italy under the Marshal de Belle-Isle, and was present during the captures of Nice, Villefranche, Montalbán and Ventimiglia.

[8] In 1762 Crillon moved to Spain, where he served as a lieutenant-general – the highest rank in the Bourbon armies – and was made a Knight of the Order of Charles III in 1780.

During the Anglo-Spanish War, when Spain and France allied with the Americans to fight Britain, he was given command of a Spanish army tasked with capturing Minorca from the British.

The siege was concluded successfully on 5 February 1782 when the British surrendered, for which Crillon was made a grandee of Spain and took the title of Duke of Crillon-Mahon.

[12] During the siege of Gibraltar, he sent his English opponent General George Eliott a gift of fruits, vegetables and game, along with some ice, which he presumed "will not be disagreeable in the excessive heat of this climate at this season of the year."

"[13] Five years later, when his old adversary Eliott was promoted to the peerage and became Lord Heathfield, Crillon wrote to his "dear and respectable enemy", whom he now considered a friend, to offer his congratulations.

His first wife, whom he married on 1 February 1742, was Françoise-Marie-Elizabeth Couvay, with whom he had two children: Louis-Alexandre-Nolasque-Félix de Balbe Berton, who became the 3rd Duke of Crillon on his father's death and had a distinguished military career in his own right; and François-Félix Dorothée.