Madrid, Alto del León, located to the west of Somosierra. When they arrived at the pass they found that it had already been occupied by a group of militiamen from Madrid, but they managed to evict them from there and on July 25 it was already in their possession. Neither the columns of Escámez or Serrador advanced towards Madrid due to lack of ammunition and they took shelter preparing to resist the attack of the republican forces. Their situation became desperate in the following days, until finally the ammunition that General Franco had sent from Andalusia arrived. A government column under the command of Colonel Mangada left Madrid in the direction of Ávila to try to isolate the rebel forces occupying Alto del León from the rear. In his advance Mangada conquered several towns in which the civil guard had joined the coup but did not go beyond Navalperal de Pinares, fearful of losing communication with Madrid and being isolated. The propaganda of the rebels attributed that decision to the "intervention" of Santa Teresa de Ávila who had deceived Mangada by telling him that Ávila was "full of armed men". Commander of the civil guard Lisardo Doval, well known for having led the brutal repression that followed the defeat of the Revolution of Asturias, tried but failed to stop Mangada's advance. Doval's failure gave Mangada a great reputation that earned him a promotion to the rank of general despite the fact that he had not fulfilled his mission of taking Avila. The columns of militiamen and volunteer soldiers who tried to evict the rebel troops from the pass of Somosierra were commanded by the brothers Francisco Galán, lieutenant of the Civil Guard, and José María Galán, lieutenant of the Carabineros, joined by prominent leaders of the Madrid CNT such as Cipriano Mera and Teodoro Mora. Captain González Gil organized the so-called "October" Battalion with workers from the aeronautical industry, among others. The idea of putting loyal professional officers in command of the militia columns, or at least advising their bosses, came from General José Riquelme, who was in command of the troops in Madrid and the 1st Organic Division. Of the militia units that fought in the Sierra de Guadarrama the most famous was the Fifth Regiment, organized by the Communist Party of Spain. Their starting point had been the communist militia (MAOC) and the "La Pasionaria" battalion formed in