He was named commander of the Army of the Left and suffered a serious defeat at the Battle of the Gebora after which he was kept from command. Utterly humiliated, Mendizábal begged to serve as a simple rank and file soldier, a request that was granted. After distinguishing himself at the Battle of Albuera in May 1811, he was reinstated by the courts with the title of Commander of the Seventh Army or "Séptimo Exército" which he took to the north of Spain in the territories that make up the Basque Provinces (Biscay), Navarre, La Rioja, Burgos, and Santander. He fought in this mountainous region using guerrilla tactics.