There are many theories as to the history of the Chihuahua, but none have been proven to be the absolute truth. One theory goes back to the fifth century A.D. where the existence of Chihuahuas is seen in central and southern regions of Mexico as well as the southern part of America.
The Mayan Indians had clay sculptures that looked much like the present-day Chihuahua. Also, when the Toltecs conquered southern Mexico in 1100 AD, they brought a small dog called a Techichi. The dog had long legs and a humped back. These dogs were used in religious rites and were kept as pets.
The Aztecs took over after the Toltecs and the Techichi was adopted into their culture as well. This dog's remains were found in both pyramids and graves, leaving researchers to believe that the dogs were also popular in the Aztec religion.
When Mexico was invaded by the Spanish, they brought with them a terrier which bred with the Techichi. This crossing was the beginning of today's Chihuahua, which is now considered to be one of the first dogs of the Americas.