After negotiations with Montezuma, who tried to persuade Cortés not to enter the Aztec capital city of Tenochtitlán, Cortés started his famous march inland. He overcame the native Tlaxcalans and then formed an alliance with them against the Aztecs, their enemies.
From that time until the conquest was achieved, the Tlaxcalans continued to be the most important of all the native allies of the Spaniards.
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