He was a military officer with no illusions about human relations, and an amateur writer; however, his initial plan was to "write a work which departed from the ordinary, which made a noise, and which would remain on earth after his death"; from this point of view he mostly attained his goals with the fame of his masterwork Les Liaisons dangereuses.

Born in Amiens into a bourgeois family, in 1761 Laclos began studies at the School of Artillery of La Fère, ancestor of the École Polytechnique.

[2] Despite a promotion to the rank of captain (1771), Laclos grew increasingly bored with his artillery garrison duties and with the company of soldiers; he began to devote his free time to writing.

[4] In 1779, he was sent to Île-d'Aix (in present-day Charente-Maritime) to assist Marc René, marquis de Montalembert in the construction of fortifications there against the British.

Durand Neveu published Les Liaisons Dangereuses in four volumes on 23 March 1782; it became a widespread success (1,000 copies sold in a month, an exceptional result for the time).

In 1788, Laclos left the army, entering the service of Louis Philippe, Duke of Orléans, for whom, after the outbreak of the French Revolution in 1789, he carried forward with intense diplomatic activity.

Eventually, Laclos met the young general and recently appointed (November 1799) First Consul, Napoleon Bonaparte, and joined his party.

Made commander-in-chief of Reserve Artillery in Italy (1803), Laclos died shortly afterward in the former convent of St. Francis of Assisi at Taranto, probably of dysentery and malaria.