Battle of El Mazuco - Definition and Overview

The Battle of El Mazuco was fought in September 1937, between the Republican (government) and Nationalist (rebel) armies of the Spanish Civil War. The Republican defence of El Mazuco and the surrounding mountains halted the Nationalist advance into eastern Asturias, despite their forces being outnumbered seven-fold. After weeks of intense fighting over extreme terrain the defenders were eventually overwhelmed, and the Nationalists were then able to link up with their forces advancing from León, leading to the fall of Gijón and the abandonment of Asturias, the last Republican province in North-West Spain.

In this battle, carpet bombing was used for the first time on a military target.

Prelude

Following the fall of Bilbao and the defeat of the Republican forces defending Santander, the Republican stronghold of Asturias was isolated from the Republican armies in the South and East of Spain. The leader of the Nationalist forces surrounding Asturias, General Dávila, attacked from the south and from the east, expecting little resistance from the demoralized Republicans.

The first republican line, along the Deva river, was soon overrun, and the town of Llanes fell on the 5^th (of September 1937). However, the routes the Nationalists had to take were now commanded by the limestone walls of the Sierra del Cuera on the north of the front and the Deva Gorge to the south. The Nationalists had to clear the defenders from these mountians in order to advance, and to do that they planned a pincer movement moving south-west from Llanes and west from Panes towards Cabrales.

On both fronts, the rugged terrain and stiff resistance of the Republicans halted the advance. It became clear that these mountains were vital to the defence of Asturias, and the key to the Sierra del Cuera was the pass of El Mazuco.

The Combatants

The Nationalist forces comprised four Navarrese Brigades (33,000 men), with 15 artillery batteries and strong air support (including the German Legión Cóndor). The pass of El Mazuco is only 5km from the sea, and so the cruiser Admiral Cervera was also able to use its guns in the action.

The Asturian and Basque forces (Republicans) comprised three weakened brigades (fewer than 5,000 men in all) with little artillery and no air support.

The Battle

The attack on El Mazuco begins with an assault by the nationalist Navarrese I brigade on the 6^th September. This is repulsed, and at the same time the southern advance of the pincer movement is also stopped. In response to these setbacks, the German Condor Legion is called in and for the first time carpet-bomb a military target, the Republican forces defending the approach to El Mazuco.

On the 7^th, further attacks are halted and the fronts stabilize; a noted republican commander, Higinio Carrocera, arrives, with three battalions and 24 heavy machine guns. Carpet-bombing with exposive and incendiary bombs continue all day.

On the 8^th, in dense fog, fierce hand-to-hand fighting inflicts severe losses on both sides. The nationalists gain some 2km on the southern front, which the republicans are unable to recapture.

On the 9^th, the nationalist pound the positions defending El Mazuco, and two republican battalions are forced to retreat, though the nationalist are unable to take any advantage of it. For the rest of that day and the next, waves of bombings and artillery bombardment were each followed by a nationalist infantry attack, each in turn cut down and turned back by the republican machine-guns.

On the 10^th, in fog again, an all-out attack by the I Brigade takes the hill of Biforco (below the pass of El Mazuco), but this is still dominated by the heights of Llabres, from where the republicans hammer the area and roll down carbide drums filled with explosive. For the first time since the start of the battle, hot food reaches the republican front lines.

On the 11^th and 12^th, on the southern front, the nationalists cannot make progress along the valley, so have no option but to advance up the ridge of the Sierra towards Pico Turbina. This peak, at 1,315m, is a formidable obstacle with slopes of 40° and an almost moon-like karst terrain. There are no tracks, even mules fall, so supplies and ordinance are largely carried by hand. The weather is bad, so aircraft cannot operate, but this also hides the attacking forces.

On the 13^th, to the north-west of El Mazuco, the republican front begins to weaken under the relentless artillery bombardment.

On the 14^th, the republicans are forced to yield Sierra Llabres, whose height commands both the village of El Mazuco and the western approaches. El Mazuco must be considered lost. Further south, Turbina is almost taken, but the attack is driven back with hand-grenades, in confused fighting in dense fog.

On the 15^th, El Mazuco and its surrounds are occupied, and the republicans in that sector fall back to Meré. To the south, the republicans still hold the heights of Turbina and Peñas Blancas. On the 16^th, Turbina is taken, and Peñas Blancas is almost encircled as Arangas and Arenas fall to the nationalists.

The three summits of Peñas Blancas now form the only salient from the republican line along the Bedón river. Initial nationalist assaults fail, and so sixteen battalions are brought up to reduce the positions. Air support is minimal due to the weather, and on the ground, rain turns to snow on the heights.

On the 18^th, better weather at noon brings three waves of airborne strafing from 'strings' of German and Italian fighters. After each attack, the inevitable infantry assault is beaten off by machine guns and hand grenades. For four full days, the pattern is repeated: aircraft and mortars pound the remaining defenders, the Navarrese infantry attack, and are repulsed. Until the 22^nd  "the red flag will wave on the highest peak". On that day, Peñas Blancas was overrun.

Aftermath

The defence of El Mazuco offered the hope of stemming the Nationalist advance until winter; if that had been achieved, then the course of the war would have been different. As it was, the attackers suffered a costly delay. The defenders regained their honour, battered in Santander, but also at great cost. The third parties involved, notably the Condor Legion, learned many lessons which could then be applied in the European theatre of the World War than followed.

The defence of El Mazuco also allowed the republicans further West a certain breathing space and a chance to regroup, but ultimately this made little difference once the Nationalists on the Eastern front joined up with the forces advancing from León and closed in on Gijón, the last republican stronghold in Northern Spain, which fell within a month.

Source

El Mazuco (La defensa imposible) by Juan Antonio de Blas, in La guerra civil en Asturias, Editiones Jucar, Gijón 1986.

[1] (http://es.geocities.com/paisajes_guerrilla/mazuco.html)
(Web page verified against original book 11/2004.)