Anarchist Organisation is the first English-language history of the 30,000-member Federacion Anarquista Iberica (FAI), the unique organisation of Spanish anarchists based on autonomous affinity groups. Dictatorship forced thee FAI underground and its members into exile; however, it was revived throughout Spain in the post-Franco years and continues to exist to this day. This first-hand account traces the history of Spanish anarchism back to the founding of the FAI in Valencia in 1927 and follows the FAI’s development throughout the crucial Civil War years, dealing with its organizational principles, controversies, objectives, and programmes. Juan Gomez Casas was active in the Libertarian Youth during the Spanish Revolution. In 1947 a military tribunal sentenced him to thirty years in prison for belonging to an illegal organization, nearly fifteen of which he served. He later acted as secretary of the national labour organisation CNT in the post-Franco period and continues to be actively involved in the CNT today. Casas has written several books and has translated a number of others in Spanish, of which Herman Melville’s Moby Dick was the first.