Alexandre-Emmanuel-François Janson de Sailly (1782-1829) was a wealthy Parisian lawyer, who found out that his wife Marie-Jeanne Joséphine Berryer had a lover.
Therefore, he decided to disinherit her and to bequeath all of his fortune to the State, under the condition that it be used to establish a modern high school that would offer an excellent education and in which no women would be allowed.
They faced the German divisions in Alsace (especially in the battles of Masevaux and Colmar) during the counter-attack of Ardennes, and entered Germany with General Patton's forces in 1945.
[3] Commemorative plaques near the entrances of several classrooms and halls in the school buildings honor the memories of its alumni - including the war hero Roland Garros.
[11] Due to its geographical location, and to the number of its important alumni, Janson de Sailly has a high reputation.
[12] According to the sociologists Michel Pinçon and Monique Pinçon-Charlot the school is predominantly attended by children from the upper class or from the aristocracy because of its location (the wealthy 16th arrondissement of Paris).