Assault Guard badge

A key reason why the coup neither fully succeeded nor completely failed was the divided response of the military and public security forces. The Army split in two. Of the eighteen divisional generals who made up the top ranks of the Spanish military, only four joined the uprising: Franco, Goded, Queipo de Llano, and Cabanellas. Of the thirty-two brigadier generals, eighteen rebelled. In contrast, the rebellion was more widespread among General Staff officers—80 per cent of whom joined the uprising. The sixty thousand members of the public security forces were evenly split: half rebelled and half remained loyal to their oath, though the breakdown varied somewhat by branch. Just over 50 per cent of the Civil Guard and the Assault Guard supported the uprising, while only 30 per cent of the Carabineros Corps took part. Thus, the first battleground of the civil war were the barracks.

This division and the ways it played out in different parts of Spain proved decisive in the outcome of the first clashes. The Republican victory in the initial battle for Madrid was built on the combined contribution of the Air Force, artillery, Civil and Assault Guards, and volunteer battalions. The Air Force and artillery provided military effectiveness and strategic utility, but also delivered a crucial psychological blow—lowering enemy morale during the siege. The use of artillery was particularly surprising for the insurgents, as they were unaware that the Republicans had regained control of the First Light Regiment. Equally crucial was the role of the Civil and Assault Guards as the main shock troops. Having the full loyalty of the Civil Guard corps was a major symbolic triumph for the Republic.

Something similar happened in the rest of the country, where the decision by the security forces to join or not join the coup tipped the balance. Across Spain, authorities and union committees tried to organize the resistance, but they lacked the weaponry needed to fight the insurgent forces effectively. Whether or not they had the support of armed units with combat experience made the difference.

Thus, the Republic managed to defeat the rebellion in those territories where it could rely on the strong action of parts of the Army and security forces that remained loyal to the legitimate government, and who in turn were supported by hastily armed militias from workers’ organizations. This was the case in Madrid, the military region of Catalonia, Valencia, and much of rural Andalusia. However, in areas where soldiers and guards joined the coup en masse, Republican resistance was crushed.

PMC