The "Bakunin" Btn. was created in Bilbao, at the Cuartel Escuela de Ingenieros de la Casilla. During October 1936 they were sent to Amurrio for training using the Reformatorio as barracks. Command was given to a professional army officer Angel Fernandez Perez who had been a sergeant in the Army of Africa "Legion Extranjera" a capable man but ill disciplined.

Soon command was transferred to Militia commander Isaac Olmos Rojo, with Sebastian Mendivil Urquijo his ltnant and aide-de camp ( who was a socialist - Not unusual, and we already know other situations like the CNT member Cipriano Mera leading succesfully the Carabineros )

The Battalion was formed only with CNT militia volunteers, mostly from Guipuzcoa and Vizcaya, plus a bunch of men from Navarra and Alava who had deserted from the Nationalist side.

Composition

The Btn. was composed as follows: Commander and ltnant liason, a Medical Service Section under the command of a Captain of medicine doctor, a Supply Section under the command of a Comandante with two trucks and a van for transport purposes, 16 donkeys for transport , and a complete fully equipped kitchen. A Dinamiteros section under the command of a lieutenant which was well equipped with explosives and two 81mm mortars. Four infantry (rifle) companies, each under a Captains command. A Machine Gun company under a Captains command. A group of specialists from the Eibar factory was in charge of weapons maintenance.

Some of the dinamiteros were from Asturias, their commander a lieutenant nicknamed "Tubines"

Service

November 1936, the Bakunin Btn. was sent to the 3rd column of the Cuerpo de Ejercito de Euzkadi for the offensive against Vitoria and Miranda de Ebro in an attempt to relief pressure against Madrid ( the 1st column under Ibarrola with 6 btns, the 2nd under Ltnant colonel Cueto, with 13 btns., and the 3rd under Aizpuru commnad with 6 btns. plus a reserve of 4 btns under Ltnant. Colonel Irazbal).

The action was under Llano de la Encomienda guidance and liability as Commander of Ejercito del Norte, although being in Bilbao, he did not participate in the offensive, Aguirre was Commander of XIV Army, and Captain Ciutat and Captain Armbarri the directors of the offensive guidelines.

November 30th the action began under a cold and rainy weather fighting the Bakunin Btn. at the right flank of Villareal, although receiving orders to avoid direct participation until December 5th . Their objective was Murguia village. Once arriving at the village against mild opposition they received orders to withdraw to original positions.

From December 6th-to 24th the nationalists recovered most of the lost territory ( details of the Villareal battle can be read in Martinez Bande "La campana el Norte", or "El Miliciano").

Following Northern Armies HQ Order 26.4.1937, all militia volunteers became Republican soldiers and the Bakunin Btn converted to the 21st Infantry Btn. under the command of Isaac Olmos Rojo and Sebasti n Mendivil Urquijo . Assigned to the 5th Basque Brigade under Captain J.Paneda a former Guardia de Asalto officer. This Brigade was a part of the 4th Division, XIV Army Corps.

In May the Brigade was sent to Sollube heights, and put against the Italians and Moors. This position was lost with heavy casualties in the second week of June, and the unit had to withdraw to Munguja. The Bakuni's Btn officer, Olmos is wounded and replaced by Julio Martinez nicknamed "Lenin" (in an anarchist unit!). Due to great pressure the btn, redeployed to Lejona, and later at Penascal besides Bilbao.

Due to enemy pressure, a new withdraw put them by the River Cadagua in the Baracaldo area, alongside with Basque Btn. 16 which had a weird and cowardly attitude. Orders included demolition of Zorroza-Burcena bridge and the railway bridges, these being opposed by the Basque nationalist's. Baracaldo was captured and the Basque 16th Btn surrendered without offering a fight . The 21st retreated to Ota¤es lines in a desperate attempt to stop the Nationalist's, and later to the Escudo Mountain where they fought fiercely against the Italian CTV. Pushed by the italians they arrived to Santander where most of the remaining unit escaped from the town on the steamer "Vapor Aller" towards France. The Italian destroyer "Denis"appeared and threatened to sink the steamer, guiding the anarchist militia as prisoners to Santurce harbour. The Bakunin Btn. official logbook was thrown into the sea, and the survivors future was the prison camp and/or the execution squad.

Main Source
Sebastian Mendivil memoirs