Anarchism and Esperanto are strongly linked because of their common ideals of social justice and equality.
Anarchists and anarcho-syndicalists (who belonged to the largest group of proletarian Esperantists before World War I) founded Paco-Libereco (Peace-Freedom),[1] an international league which published the newspaper Internacia Socia Revuo (International Society Review).
Paco-Libereco merged with another progressive association, Esperantista Laboristaro (Esperanto Workers).
In March of 1925, the Berlin Group of Anarcho-Syndicatist Esperantists ("Berlina Grupo de Anarki-Sindikatismaj Esperantistoj") met with the 2nd Congress of the International Labor Association (ILA) in Amsterdam.
After World War II, the Paris group was the first to restart organized labor.