Spanish Civil War's 1936 Chekas and Post‑1934 Revolutionary Violence

In the summer of 1936, after the military uprising of 18 July, major Republican cities such as Madrid, Barcelona and Valencia saw the rapid emergence of clandestine detention centres called “checas”. Modelled on the Soviet Cheka and run by socialist, communist and anarchist militias – sometimes with Soviet advisers – they carried out arrests, torture and summary executions. Sources record more than 340 checas in Madrid, at least four per square kilometre, and similar facilities in Barcelona (e.g., the San Elías checa) and Valencia’s convent of Santa Úrsula.

The same period continued the violent fallout of the October 1934 “Revolution”, an armed uprising by the PSOE‑UGT that killed around 1 500 people and wounded 3 000, especially in Asturias. The July 1936 coup enabled the military, led by officers such as Francisco Franco, to punish participants of the 1934 revolt, leading to further killings. A subsequent amnesty later freed thousands of political prisoners.