By June 1937, the Republic was running out of options. Bilbao had fallen to the Nationalists on June 19. Soviet aid was dwindling because the Nationalist naval blockade was strangling Republican ports. Prime Minister Juan Negrin needed to convince France to reopen its border for arms shipments, and the communists were pressing Moscow's case for a dramatic show of force. Two previous offensives -- at Huesca in Aragon and near Segovia -- had already failed. Brunete was chosen because it sat on the Extremadura road, the main supply route for Nationalist forces besieging Madrid. If the Republicans could cut it, Franco's troops around the capital might be forced to withdraw. Soviet advisors had been urging the attack since spring. The terrain -- hilly but open, accessible to the Republic's new Soviet tanks -- seemed favorable for the first time.

Lister's 11th Division advanced eight kilometers on the first day, encircling Brunete and capturing it by noon. But the flanking attacks stalled. The villages of Quijorna and Villanueva de la Canada held out, absorbing Republican units that should have been exploiting the breakthrough. The Republican command, apparently surprised by its own initial success, hesitated to commit reserves, and the deployment of the XVIII Army Corps was delayed by confusion and skepticism among non-communist officers. Meanwhile, the Nationalists moved with speed that belied their surprise. General Varela took command and rushed every available soldier to the front -- staff officers, hospital personnel, supply troops. By afternoon, the Condor Legion was en route. The planned pincer attack from Carabanchel, south of Madrid, never broke through at all.

What followed was nearly three weeks of attritional fighting in conditions that broke men as efficiently as the combat itself. Temperatures soared. Water ran short. Artillery bombardments ignited wildfires across the parched landscape. In the air, formations of thirty or more aircraft clashed in dogfights that would have been remarkable in any theater of the war, but the Republican planes were slower and older, and the Condor Legion gradually seized control of the sky. By July 15, General Miaja ordered the offensive halted. The Republicans held Brunete and had cut the Extremadura road, but many brigades had lost 40 to 60 percent of their strength. The XIV International Brigade reportedly lost 80 percent. On July 18, the British poet Julian Bell was killed by bomb fragments while driving an ambulance for a volunteer medical unit.

Varela's counteroffensive struck with three prongs and overwhelming artillery superiority -- 65 batteries against 22 Republican. On July 24, Nationalist forces breached the lines south of Brunete and entered the town. Lister's 11th Division fell back to the cemetery and held for a day before withdrawing. On July 25, as the battle sputtered to its conclusion, the German war photographer Gerda Taro was fatally wounded when the car she was traveling in was struck by a Republican tank spiraling out of control during a Nationalist air attack. She was 26 years old. Franco halted Varela's advance to redirect troops north for the coming assault on Santander. Both sides claimed victory, but the Republic had lost irreplaceable equipment and many of its best soldiers from the International Brigades. The communists lost political prestige. The Condor Legion's effectiveness earned Germany favorable trade concessions and most-favored-nation status from the Nationalists.

The terrain west of Madrid where the battle was fought remains hilly, dry, and largely open -- much as it was in July 1937. Brunete itself is now a quiet commuter town. The battle was later commemorated in the name given to the Spanish Army's Armoured Division No. 1 "Brunete," formed in the mid-1940s. But the real legacy is in what the battle revealed: that the Republic could mount a serious offensive but could not sustain one, that air superiority was becoming decisive, and that the international volunteers who fought in Spain's war were paying a price far beyond what most of their home countries understood. Among the dead were soldiers, poets, and photographers whose work would outlast the cause they served.