Ernest "Ernestan" Tanrez (15 July 1898 – 17 February 1954) was a theoretician of Libertarian socialism and an important figure in Belgian anarchism.

[1] Despite being a Flemish (Dutch) -speaking region, in the northern part of Belgium, including Ghent, members of the intellectual and mercantile classes frequently used French as a first language in the home during this period.

[2][3] He was just 16 when war broke out in 1914: he was obliged to terminate his studies early and escape to France where he discovered the writings of the pacifist writer-philosopher (and Nobel laureate), Romain Rolland.

Deeply affected by the horrors of the First World War, Tanrez began to frequent avant-garde circles and to participate actively in the Anarchist Movement.

[1][5] In June 1921, using the pen name by which he would subsequently become known, "Ernestan", he began to write for the Belgian libertarian press, starting with the "Bulletin libertaire", the principle periodical of the Brussels anarcho-libertarian community.

The publication gave the address of its editorial office as the "Café du cygne", centrally located in Brussels' iconic "Grand-Place" / "Grote Markt" / "Main Square".

"Combat" was also published by Camille Mattart, in this case as a joint production with "Hem Day" (as Marcel Dieu was known to readers).

[2][5] High-profile causes in which he participated included sustained support for Nicola Sacco and Bartolomeo Vanzetti, two Italian anarchists who emigrated to North America and, during the 1920s, faced trial for a series of capital crimes.

A couple of months before the Hitler government took power in early 1933 "Ernestan" became one of the first to join the "Hem Day" committee's anti-conscription campaign, returning the government-issued document in respect his military record ("Livret militaire"), standing up for the right to conscientious objection and, in that context, helping to intensify the public pressure that secured the early releases of Marcel Dieu (1902–1969) and Léo Campion (1905–1992) at the end of 1933.

Two editions were produced in Brussels in May and August 1937, to be followed by a successor publication "L’Espagne Nouvelle", printed at intervals between 1937 and 1939 using production facilities at Nîmes made available by the fellow antifascist André Prudhommeaux.

[3][4] By the time Tanrez was freed from Camp Vernet, in August 1940, northern France and Belgium were both under direct German occupation and a measure of uneasy calm had resumed.