[2] He received his training in the studio of Jacques-Louis David, (the leading Neoclassical French painter) and became one of his favorite students.

The two artists worked together on several important paintings, including Napoleon crossing the Alps (now at the Kunsthistorisches Museum in Vienna), in which Langlois painted the horse, and Leonidas at Thermopylae (Musee du Louvre, Paris).

A preparatory drawing of the painting that granted him the first place (Priam aux pieds d'Achilles) is in the collection of the Musee Magnin in Dijon, France.

Langlois's Diana and Endymion of 1822 was commissioned by Louis XVIII for his Salon of Diane at the Palace of Versailles.

[6] In 1817 his painting Cassandra Imploring the Vengeance of Minerva Against Ajax was exhibited at the 1817 Paris Salon and earned a second-class medal.