weaken under the relentless artillery bombardment, and the Republicans were forced to yield Sierra Llabres, whose height commands both the village of El Mazucu and the western approaches on 14 September. The village of El Mazucu itself was then indefensible. To the south, Pico Turbina was almost taken, but the attack was driven back with hand-grenades, in confused fighting in dense fog. El Mazucu and its surrounds were occupied on 15 September, and the Republicans in that sector fell back to Meré. To the south, the Republicans still held the heights of Pico Turbina and Peñas Blancas (the summits of Peña Blanca). Pico Turbina was taken, and Peña Blanca was almost encircled as Arangas and Arenas fell to the Nationalists the next day. The three summits of Peñas Blancas now formed the only salient from the Republican line along the Bedón river. Initial Nationalist assaults failed, and so sixteen battalions were brought up to reduce the positions. Air support was minimal due to the weather, and on the ground, rain turned to snow on the heights. The better weather on 18 September at noon brought three waves of airborne strafing from 'strings' of Junkers and Fiat fighters, and possibly Heinkel 51s based on the Cue Aerodrome. After each attack, the inevitable infantry assault was beaten off by machine guns and hand grenades. For four full days, the pattern was repeated: aircraft and mortars pounded the remaining defenders, the Navarrese infantry attacked, and were repulsed. Until 22 September "the red flag waved on the highest peak". On that day, the Peñas Blancas were finally overrun. Aftermath The defence of El Mazucu 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 were later applied in the European theatre of the World War that followed. The defence of El Mazucu also allowed the Republicans further west in Asturias a certain breathing space and a chance to regroup, but ultimately this made little difference. The Nationalists on the Eastern front soon joined up with the forces advancing from León at Infiesto, and closed in on Gijón. Gijón, the last republican stronghold in Northern Spain,