This era saw Barcelona become one of the most politically radical cities in Europe. As industrialization matured, workers organized into unions and anarchist federations, leading to strikes, uprisings, and deep class divides. The Tragic Week (1909) revealed growing tensions, while the 1920s and 30s brought dictatorship, fleeting democracy (Second Republic), and finally the Spanish Civil War (1936–39). During the war, anarchists and leftist groups effectively ran the city, transforming workplaces and society before Barcelona fell to Franco’s forces in 1939.