The Battle of Penco, on March 12, 1550, was a battle between 60,000 Mapuche under the command of their toqui Ainavillo with his Araucan and Tucapel allies and Pedro de Valdivia's 200 Spaniards on horse and afoot with many yanakuna including 300 Mapochoes auxiliaries under their leader Michimalonco, defending their newly raised fort at Penco. Wikipedia