men in all), under the command of Colonels Juan Ibarrola Orueta and Francisco Galán Rodríguez (Ibarrola and Galán) in Meré, with little artillery and no air support. The battle The attack on El Mazucu began with an assault by the Nationalist Navarrese I brigade on 6 September. This was repulsed, and at the same time the southern advance of the pincer movement was also stopped. In response to these setbacks, the German Condor Legion was called in and for the first time carpet-bombed a military target, the Republican forces defending the approach to El Mazucu. On 7 September further attacks were halted and the fronts stabilized; a noted Republican commander, Higinio Carrocera, arrived, with three battalions and 24 heavy machine guns. Carpet-bombing with explosive and incendiary bombs continued all day. The next day in dense fog, fierce hand-to-hand fighting inflicted severe losses on both sides. The Nationalists gained some 2 km on the southern front, which the Republicans were unable to recapture. The Nationalists used the following day to shell the positions defending El Mazucu, and two Republican battalions were forced to retreat, although the Nationalists were unable to take advantage of the withdrawal. 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. The fog having returned on 10 September, an all-out attack by the I Brigade took the hill of Biforco (below the pass of El Mazucu), but this was still dominated by the heights of Llabres, from where the Republicans hammered the area with machine guns and rolled down carbide drums filled with explosive. For the first time since the start of the battle, hot food reached the Republican front lines. During the next two days, on the southern front, the Nationalists could not make progress along the valley, so had 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 were no tracks, even for mules, so supplies and ordnance were largely carried by hand. The weather was bad, too, so aircraft could not operate – but the fog also hid the attacking forces. By 13 September the Republican front to the north-west of El Mazucu began to