45: The Battle of Brunete


Two Republican attacks were launched in the hope of forcing forces to be moved from the north to other areas of Spain. These two attacks, at Guadarrama and Huesca will be our first topic for this episode. However, the primary focus will be on the battle of Brunete. This attack would be launched in July 1937 by the Republican Army and it would achieve one of its goals of forcing the Nationalists to move troops away from their attacks in the north, even if it was in reality too late to halt the collapse of the enclave. The Republicans would commit their best troops, and most of their armor assets, to the attack at Brunete and the failure of the attack would begin a clear decline in the fighting capabilities of the Republican forces, from which they would never really recover.


Listen to “45: The Spanish Civil War Pt. 10 - The Battle of Brunete” on Spreaker.


  • The Battle for Spain by Antony Beevor
  • Spain in Arms: A Military History of the Spanish Civil War 1936-1939 by E.R. Hooton
  • The Spanish Civil War A Modern Tragedy by George R. Esenwein
  • Spanish Civil War Tanks: The Proving Ground for Blitzkrieg by Steven J. Zaloga
  • The Anarchist Collectives: Workers’s Self-management in the Spanish Revolution 1936-1939 Edited By Sam Dolgoff
  • Patterns of Development and Nationalism: Basque and Catalan Nationalism before the Spanish Civil War by Juan Diez Medrano
  • Blackshirts, Blueshirts, and the Spanish Civil War by John Newsinger
  • Edge of Darkness: British ‘Front-Line’ Diplomacy in the Spanish Civil War, 1936-1937 by Tom Buchanan
  • Franklin D. Roosevelt and Covert Aid to the Loyalists in the Spanish Civil War, 1936-39 by Dominic Tierney
  • The Cult of the Spanish Civil War in East Germany by Arnold Krammer
  • Fascism, Fascitization, and Developmentalism in Franco’s Dictatorship by Ismael Saz Campos
  • Writing the Female Revolutionary Self: Deoloris Ibarruri and the Spanish Civil War by Kristine Byron
  • A Spanish Genocide? Reflections on the Francoist Repression after the Spanish Civil War by Julius Ruiz
  • The Spanish Civil War in the 21st Century: From Guernica to Human Rights by Peter N. Carroll
  • The Revolutionary Spirit: Hannah Arendt and the Anarchists of the Spanish Civil War by Joel Olson
  • Seventy Years On: Historians and Repression During and After the Spanish Civil War by Julius Ruiz
  • Fascist Italy’s Military Involvement in the Spanish Civil War by Brian R. Sullivan
  • The Spanish Civil War: Lessons Learned and Not Learned by the Great Powers by James S. Corum
  • Truth and Myth in History: An Example from the Spanish Civil War by John Corbin
  • ‘Our Red Soldiers’: The Nationalist Army’s Management of its Left-Wing Conscripts in the Spanish Civil War, 1936-39 by James Matthews
  • Multinational Naval Cooperation in the Spanish Civil War, 1936 by Willard C. Frank Jr.
  • ‘Work and Don’t Lose Hope’: Republican Forced Labour Camps During the Spanish Civil War by Julius Ruiz
  • The Spanish Civil War, 1936-2003: The Return of Republican Memory by Helen Graham
  • Soviet Armor in Spain: Aid Mission to Republicans Tested Doctrine and Equipment by Colonel Antonia J. Candil, Spanish Army
  • The Soviet Cinematic Offensive in the Spanish Civil War by Daniel Kowalsky
  • Soviet Tank Operations in the Spanish Civil War by Steven J. Zaloga
  • The Spanish Military and the Tank, 1909-1939 by Jose Vicente Herrero Perez
  • The Theory and Practice of Armored Warfare in Spain October 1936-February 1937 by Dr. John L. S. Daley


Hello everyone and welcome to History of the Second World War Episode 45 - The Spanish Civil War Part 10 - The Battle of Brunete. This week a big thank you goes out to Roxie, Tommy, Chris, Curtis, and Calvin for their support on Patreon, where they get access to ad free versions of all of the podcast’s episodes plus special Patreon only episodes released once a month. If that sounds interesting to you head on over to historyofthesecondworldwar.com/members to find out more information. While the Nationalist offensive against the Republican northern enclave was occurring, and the defense against that offensive was going quite poorly, the Republican government began to consider the next Republican attack. The shift of Nationalist focus away from Madrid allowed the main Republican military forces a moment to breath, recover, and to consider this next move. The speed of the Nationalist victories would then derail some of the preparations that were being made and would force two Republican attacks that were launched in the hope of forcing forces to be moved from the north to other areas of Spain. These two attacks, at Guadarrama and Huesca will be our first topic for this episode. However, the primary focus will be on the battle of Brunete. This attack would be launched in July 1937 by the Republican Army and it would achieve one of its goals of forcing the Nationalists to move troops away from their attacks in the north, even if it was in reality too late to halt the collapse of the enclave. The Republicans would commit their best troops, and most of their armor assets, to the attack at Brunete and the failure of the attack would begin a clear decline in the fighting capabilities of the Republican forces, from which they would never really recover.

While Brunete would become the central focus of the Republican army during the summer of 1937, it was not the original plan for the 1937 offensive. Instead the initial thinking was for an attack in southwestern Spain. This would have the goal of driving west into Nationalist territory and then pushing to the Portuguese border through the Estremadura region, splitting Nationalist territory into two pieces. There were two primary problems with this plan, first, it would be challenging to deploy the forces necessary so far to the south while maintaining any kind of secrecy, second, the situation in the north was deteriorating far more quickly than expected. Due to how events were going in the north there needed to be action soon if it was to have any effect on the course of events. There was also some resistance to these plans from the Communist leaders and the Soviet military advisors. There was a general resistance from the Communists for any operation that did not directly effect the defense of Madrid. They had simply put too much effort into the defense of the city and they had made it the primary focus of international publicity. They saw the defense of the capital as the most important area of the war and they preferred an attack near Madrid in the Sierra Guadarrama. At this point in early 1937 Communist influence was growing, but Caballero and others within the government were still hesitant to allow this control to continue to grow. In fact one of the reasons that Caballero supported an attack anywhere but Madrid was because it would reduce Communist influence on the course of the attack. The Communists had a very important ally in their plans though, the Soviet military advisors, and they would refuse to permit any Soviet tanks or aircraft to be shifted south for the Estremadura operation. In this effort to block the flow of troops and equipment south they had the support of General Miaja, who they encouraged to not allow troops to be removed from the areas around Madrid. Technically Miaja could not prevent any ordered troops movements, but he could delay as much as possible, and these delays would last long enough for the scheduled date for the attack to pass. Among the less political officers of the Republican Army this was an important moment when they fully began to realize the power that certain groups held within the Republic, and how that could be held over the army and its plans. There were also concerns that military plans could be so openly altered not for military reasons but strictly due to the propaganda requirements of the Communists. Eventually the attack was officially put on hold and then cancelled when Caballero’s government fell and was replaced by Negrin’s government.

Plans for a large attack to replace the Estremadura were underway, but in the meantime there was the immediate need to quickly launch attacks to try and take the pressure off of the enclave. To do this two attacks were planned, one near the end of may and the other a few weeks later in mid-June. The first would be based in the Sierra de Guadarrama to the northeast of Madrid on May 30th. The attack would begin with a heavy artillery bombardment of nationalist positions, and when the attack went forward the 69th division managed to make some progress. However, the next day Nationalist forces, both in the form of infantry and air assets, would be repositioned from Madrid to meet the attack. They would then counterattack after a heavy aerial bombardment. The counterattack would not be hugely successful, but it would halt any Republican advances and on June 6th, after a few days of heavy fighting, the Republican troops were ordered to move back to the positions that they had started in before the attack began. While the overall effects of this attack were small, and it in no way hindered Nationalist operations in the north, it would be an important moment for one reason. It would during this attack that serious cracks in the morale and discipline of the International Brigades began to show, as there was a growing concern that they were being sacrificed for no real reason. This was not at all helped by the fact that during the retreat from the attack one of the officers would order ‘the machine-gunning of those who pull back, executions on the spot, and the beating of stragglers.’ The officer who gave that ordered would eventually be relieved of command, but such views about the the place of the International Brigades and the role of the people within them would continue to cause problems for the rest of 1937. While the Guadarrama attack would fail to make a meaningful impact on the course of the northern offensives, another operations was launched near Huesca in north eastern Spain. In that area the attack would be launched primarily by anarchist and POUM troops, while the XII International Brigade would also be sent north to join them. This attack had some serious obstacles to overcome, like physical obstacles, in the form of very well prepared Nationalist defensive positions. When the first attack was launched on June 12th, and then for all of the attacks that would continue for a week, no appreciable gains were made. Even though they accomplished very little, thousands of casualties would be sustained, and again the wider aim of the offensive, to pull Nationalist resources away from the enclave, was not accomplished.

While the Guadarrama and Huesca efforts had been smaller attacks designed not to drastically change the overall situation but to provide relief for the north, the next Republican effort was something quite different. Once again the plan was based around the situation in Madrid. The idea for the attack originated at an earlier date, but had been refined and advocated for by Generals Miaja and Rojo. It would take place 25 kilometers west of Madrid with the overall goal of pushing through the village of Brunete and then onto the Estremadura Highway. This highway was quite important because it was the primary supply line of the Nationalist First Corps of around 50,000 men who were in positions around Madrid. This made it a very important bit of road, and much like the Nationalist attacks from 1936 the hope was that by capturing the road and preventing supplies from moving over it the positions of the troops around Madrid would become untenable. When this occurred, and when the supplies for the First Corps were cut off then other attacks would be launched with the goal of slowly squeezing them, taking advantage of their supply issues to eliminate them. The official plan, written by Rojo, called for the attack to be launched the first week of July. The commanders were told that they should expect an enemy that was generally over-extended and relatively weak. This was accompanied by orders that commanders should be bold and aggressive with their attacks to push forward rapidly, with less concern about possible Nationalist counter attacks. These efforts would have the full support of the Communist Party and Soviet forces, and they hoped that a large victory during the attack would provide a large propaganda victory. All five International Brigades would be brought in for the attack, and they were given some of the most important objectives. In total 70,000 men would be involved, including 132 tanks, over 200 pieces of artillery, and 140 aircraft. It was, far and away, the most powerful offensive that the Republicans had launched during the war. The Nationalists would not start to learn of the attack until June 30th. Their primary source of information were republican deserters who crossed the line and brought with them warnings of the planned major offensive. Throughout the early days of July this information continued to flow in with additional details being provided, like the number of troops involved and more and more specifics about the plans and objectives of the attack.

The bombardment that would precede the attack began at 5:30AM on July 6th. When the attack went forward there was progress in some areas, but in many areas they ran into the same problems. The greatest problem that would develop on the first day was the inability of the Republican troops to seize a few very important strong points from the Nationalist defenders. Some of these defenses were around and in villages, like Los Llanos where repeated Republican attacks that attempted to take the town ere met with a strong Nationalist defense and they were unable to make real progress. In some areas the defenses were simply much strong than anticipated, like in the village of Quijorna, where the Republican troops that moved into the attack found a completely intact trench system, including barbed wire entanglements that made it incredibly difficult to reach their objectives. In the village of Villaneuva de la CaƱada the defenders were hugely outnumbered by the attacks, around 9 to 1, but they continued to hang on for most of the day. After only a few hours of the attack news began to arrive back at General Miaja’s headquarters, and the reports were very concerning. Due to the continued ability of the villages and other areas to hold out after repeated Republican efforts, the ability of the rest of the Republican attack to push forward was rapidly becoming jeopardized. Along with the large numbers of Spanish units, the International Brigades were also committed at various points, but they were unable to alter the situation. Even in areas where there were successful Republican attacks, for example when the 11th Division captured Brunete itself on July 7th, the lack of success in other areas caused the commanders to favor a very cautious approach. When the 11th division to Brunete, instead of pushing forward as quick as possible, they instead began to construct defensive positions while they waited for other areas to be captured. In those areas, like the village of Quijorna, hours turned into days and still the fighting continued. In other areas of the attack, especially those that were launched by General Romero’s troops in the outskirts of Madrid, the results were even more disappointing. Here the Nationalist defenses were very strong, reminiscent of the Western Front defenses from the First World War, and the Republican units had simply no hope of making any real meaningful progress. These early failures, and hesitation to properly exploit the successes that did occur, would be capitalized on by the Nationalists. Almost immediately the planned attack in the north, which was scheduled to push into Santander, was delayed and the troops that were part of the operation began to move south. The 150th Division moved south in just a few days, all loaded into trucks that had been purchased from the United States. The 150th was joined by more troops from the north as well as Nationalist reinforcements from elsewhere as they converged on the Republican attacks. Artillery and aircraft were also brought in. While these troops and supplies were in route those that were already on the front would continue to to hold on, and after the first two days o the attack they were still doing quite well.

As I mentioned just a moment ago, it would take several days for Quijorna to fall, and only after it had been reduced to ruins. In the days that followed the opening day many similar actions took place where the Nationalist defensive positions would prove to be simply more resilient than planned, which would continue to delay entire sections of the defense. It did not help that very quick, as aviation assets were moved in, the attacks of Junker 52s and Heinkel 111s became a very frequent occurrence. During the first day of the attack the Republicans had obtained some level of aerial superiority over the Nationalists, but as soon as the Nationalist squadrons from the north began to arrive in the theater the balance of power began to shift very rapidly. Italian planes were the first to join with the Spanish squadrons and on July 6ths they were already flying sorties. By July 8th all of the Condor Legion’s 8 squadrons were in place and started their missions, joined by 6 Spanish squadrons. As other Nationalist reinforcements arrived, especially ground troops, the possibilities for the Republican attack began to shrink. The entire offensive had been based on the idea of hitting the Nationalists hard and fast, and breaking out and preventing the very likely possibility of the Nationalist reinforcements swarming the attack with reinforcements. Fighting on July 7th, and then July 8th, indicated that the breakout was probably not going to happen. All the while Nationalist troops continued to pour into the line opposite them. Some of the objectives for the first day were still resisting, even days later. On July 10th the XII International Brigade took Villanueva del Pardillo, which had cost 3,000 casualties and had acted as a huge block on any advances on the Republican left. As the attack continued day after day a shift occurred with the Republican units, and this was the shift from further attempts to expand their gains to instead trying to ensure that they could hold on to what they had already gained. Defenses were erected in the anticipation of a Nationalist counter attack. There were was also some efforts put into trying to simply supply the front line troops. During the attack there had not been enough road capacity in the area to properly supply the front line units, especially with the ever present threat of air attack which constantly disrupted the movement of supplies. While the Republican army was busy just trying to supply its troops, the Nationalist forces grew stronger and it was only a matter of time before the inevitable counterattack was launched.

General Varela wanted to launch the counter attack as soon as the 150th division had arrived and was ready, but Franco ordered a more cautious approach. Every day the Nationalist forces grew stronger, and he wanted to wait until two of the Navarrese brigades arrived from the north. The delay also allowed for Nationalist air superiority to be guaranteed and by July 13th large flights of Nationalist aircraft were flying over the battlefield completely unmolested by Republican fighters. On the 15th Miaja would officially end any further Republican attacks, stating that the army should “rest, to build up reserves to withstand any enemy offensive action in the first place, and in the second to enable offensive action on our part in the near future.” However, and critically, Miaja ordered that none of the captured territory should be evacuated. At the time, there was little need to give up their gains because the Nationalists had not yet attacked, and in fact the week before July 18th had been relatively calm on the ground. During their attacks Republican forces had sustained about 11,000 casualties, and many of them had been suffered by the best units in the Army which had been sapped of their strength. There was also no clear indication of what effects the attacks had on the Nationalists, with the information available either sketch or outright falsified. There were a few instances where Republican commanders were, lets say very loose with their estimated Nationalist troop numbers and estimated Nationalist casualties in an attempt to try and explain away their own failures. The assumed Nationalist counter attack would then begin on July 18th, with Nationalist artillery and bombers hitting Republican positions on all sectors of the salient that had been created by the attack. All forms of bombardment were assisted by the fact that Republican positions were well known after being static for several days. Even with this information the first day of attacks were less successful than hoped. There had been some planning among the Republican officers for the possibility of a Nationalist attack which would begin on July 18th, because it was the anniversary of the coup. This meant that they were more prepared than they might have otherwise been. Even with disappointing results on the first day the Nationalists were not deterred and over the next several days the attacks would continue. In sustained action the same problems that had effected the Republican units in their earlier attacks also became problematic in the long defense, with Nationalist airpower suffocating over the battlefield it quickly became more and more difficult to move ammunition and supplies forward. This meant that even after their initially successful defense the troops at the front were quickly on the verge of complete collapse due to supply shortages and the inability to move additional forces forward. The Nationalist attacks on and after July 23rd would greatly reduce the salient that had been initially created, and it would also push several Republican units to the breaking point. The XIII International Brigade would see al full mutiny after days of being on the front lines with no hot food and insufficient water, and while discipline was eventually restored, it was only after several ringleaders were executed.

At the end of the Nationalist counterattacks the Republican held on to only about half of what they had at one point been able to capture, and what was left was only about 50 square kilometers of mostly worthless territory. The casualties on both sides were quite high, with some variability in the estimates. The Republicans suffered between 20,000 and 25,000 and the Nationalists 10,000 to 17,000. More importantly than the large numbers of casualties were other problems that the failure at Brunete caused for the Republican army. They lost a very large percentage of the armor that had been committed, and a 1/3 of the aircraft in the theater. Both of these types of equipment would not be easy to replace. Brunete also represented the point where many of the best and most motivated troops that were still remaining in the Republican military would cease to exist, or at the very least cease to be effective combat units. For example the XIII International Brigade, with a total strength of a bit over 13,000 men, had nearly 4,300 casualties and 5,000 additional men in hospital after the fighting was over. Even with these problems, both the failure of the Nationalist attack to recapture all the territory or the failure of the initial attack to achieve its objectives, both sides would claim that Brunete was a great victory. The Communists would do this on a world stage, using the so called Brunete victory in their propaganda campaigns. However, in truth Brunete was a complete failure for the Republicans. The key was that the attack was able to capture little of real value, and even its usefulness as a diversion of Nationalist forces from the north would only be temporary. As discussed in a previous episode, shortly after the Brunete attack wound down the troops were back in the north and the enclave was once again under attack. While Brunete represented a Republican defeat, it did not deter them from launching offensives, and next episode we will discuss the next Republican attack at the Battle of Tereul.