 He fought at the Battle of Otumba on July 8, and also took part in the campaign against the Purépecha, who proved difficult foes due to their use of iron weapons, which the Aztecs lacked.During the siege of Tenochtitlán, Olid squabbled with Pedro de Alvarado, and refused to assist him in an assault on the causeways leading into the city.This refusal lead to a resounding Spanish defeat, and Olid fled to Coyohuacan.