However, soon, while Cortés was away, Spanish soldiers attacked and killed many Aztecs during a festival. When Cortés got back, he got Montezuma II to tell the Aztecs to stop fighting the conquistadors. By this time, though, the Aztecs had made Montezuma II's brother, Cuauthemoc, the king. Nobody did what Montezuma II said. They kept fighting the conquistadors, and they killed two out of every three Spanish soldiers. In July 1520 the Spanish survivors fled to Tlaxcala, where enemies of the Aztecs protected them.