Ernestan was the pen name of Ernest Tanrez who came from a middle class family, with a French speaking father and a Flemish mother. Deeply affected by the slaughter of the First World War, from 1921 he began writing for the Belgian libertarian press, for Bulletin libertaire and l’Emancipateur and then for the international anarchist press (le Libertaire, Combat Syndicaliste, CNT) He also published several pamphlets like Socialism against Authority and the Libertarian Socialist Manifesto.