The Iron Column was a Spanish anarchist militia column formed during the Spanish Civil War to fight the military forces of Francisco Franco that had rebelled against the Second Spanish Republic.
The Iron Column was formed in Valencia at the start of the Spanish Revolution by local anarchists including Rafael Martí (nicknamed 'Pancho Villa' after the Mexican revolutionary), José and Pedro Pellicer, Elias Manzanera and José Segarra.
The Iron Column stood for defence (and extension) of the popular revolution rather than defence of the Republic. Among its earliest acts were the liberation of convicts from the San Miguel de los Reyes prison and the burning of judicial archives. Many of these liberated convicts joined the Iron Column upon being released from jail. Alongside other militia columns, the Iron Column fought on the Teruel front.
The Iron Column resisted the government plan of turning the popular militias into regular army units longer than any other group. Reasons for this resistance can be read in an essay titled "A Day Mournful and Overcast", written by a member of the Iron Column. The Iron Column became the 83rd Mixed Brigade (with many members who had previously been delegates becoming officers) in 1937, but was dissolved later that year.