Her father, Paul Louis Weiss (1867-1945), a mining engineer, was a distinguished Alsatian Protestant from La Petite-Pierre.

[3] The ancestors of her Jewish mother, Jeanne Félicie Javal (1871-1956), originated from the small Alsatian town of Seppois-le-Bas.

In 1945, she founded the Institute for Polemology (research on war and conflict) together with Gaston Bouthoul [fr][5] in London.

In Paris, she came in contact with her first great loves, representatives of countries striving for independence, such as Eduard Beneš, Tomáš Masaryk and Milan Štefánik.

Thomas Mann, Gustav Stresemann, Rudolf Breitscheid and Aristide Briand were among her co-authors on the paper.

Europe dreamed of unification and in 1930, she founded the "Ecole de la Paix" (School of Peace), a private institute for international relations.

In 1934, she founded the association Les femmes nouvelles (The New Woman) with Cécile Brunsvicg, and she strove for a stronger role for women in public life.

Each year, the Louise Weiss Foundation awards a prize to the author or the institution which has contributed the most to the advancement of the science of peace, the improvement of human relations and efforts of benefit to Europe.