The Battle of Otumba is part of the story of the Fall of Tenochtitlan, specifically La Noche Triste. The Spanish had to flee the Aztec capital and reach Tlaxcalan, where they would find allies. After being beleaguered on the causeway leading out of the city, Hernán Cortés fled towards Tlaxcala, and was intercepted by a group of warriors of the Tenocha, Tepaneca, Xochimilco and other peoples. However, despite the fact that they had already seen horses, seeing Spanish knights in full regalia proved to have shock value, as the warriors had never seen such in open battle. The fight lasted for four hours until Cortés attacked a warrior named Cihuacóatl Matlatzincatzin, the tallest and most adorned of the attackers. He and thirteen knights charged the army's leader and killed him. This charge broke the natives’ ranks and they fled. This battle gives Otumba the denomination of "La Heroica Otumba." Despite the poor condition and heavy losses of the Spanish army and the overwhelming number of Aztec warriors, the Spanish prevailed and were able to reach Tlaxcala to regroup. Some 20,000 Aztecs were killed. While the town lends its name to this battle, it really occurred in a place called Temalacatitlán.