In 1519, the Spanish conquistador, Hernando Cortes, sailed from Europe to land in what is now Mexico. After a long journey inland, Cortes and his men saw the Aztec capital city and met the Aztec leader. The Spanish were lucky and were let into the great capital city all because of an old legend. This was their beginning of their fate. The Aztecs believed that the god of night had defeated Quetzalcoatl in a game of Tlachtli. As the winner, the god of night could decide what to do with Quetzalcoatl. The god of night decided to banish Quetzalcoatl to the East. Quetzalcoatl had no choice but to leave. He vowed that some day he would return, when the end of the world was near, to save his people and their love and legacy. The Spanish then left for a period of time. The Spanish did return, but they were much better prepared to fight the fierce Aztec warriors. It was not the Spanish guns that won the day. It was the Spanish horses and dogs. The Spanish brought huge fierce mastiffs with them into battle. Their best weapon was disease. The Aztecs had never been exposed to childhood diseases like measles. Also, the Spanish had help from the other tribes in the area. These tribes saw a chance to get even with the Aztec to rid themselves of the feared and hated Tribe. This brought the Aztec down in just 3 years.