The first highly developed civilization to emerge in the New World belonged to the Olmecs, who flourished between 1200 and  500 BC in the lowland jungles of Veracruz and Tabasco. Most readily identified with the massive stone heads they sculpted, the Olmecs are credited with originating much that would be adapted by later cultures, principally the Maya.  The Olmecs developed a calendar and hieroglyphic writing, and aspects of their religion, architecture, art and an elementary numerical system were expanded on  for centuries to come. Their influence was carried via extensive trade routes to  central Mexico, the states of Guerrero and Oaxaca, and throughout the Maya  region.

In central Mexico, the sprawling ruins we  call Teotihuacan -- a name the Aztecs gave to it, meaning "Place Where Gods Are  Made" -- was a true city that at its peak, around 500 AD, may have reached a population of 200,000, and maintained extensive contacts throughout Mesoamerica.  Who built Teotihuacan is a mystery; the city was long in ruins by the time the  Aztecs arrived.

Contemporary with Teotihuacan was Cholula, a city near Puebla, which managed to survive as a religious center through many changes in cultural dominance. It was still a revered city at the time of the  Spanish Conquest in 1521.

At this same time, the Maya were busy  building great cities that today are largely buried in the rain forests of Chiapas and Guatemala. Such leaders as Pacal of Palenque and Bird Jaguar of Yaxchilan left records of their times in hieroglyphic writing that has only  recently been decoded.

Quetzalcoatl, the Feathered Serpent, is one  of the most prominent gods of Mesoamerica. Legend has it that the fair Quetzalcoatl was forced to flee his home in central Mexico and head east to the  Yucatan Peninsula, where he became known as Kukulcan. Upon leaving, he announced that he would one day return.

Among the many wandering tribes of the north were the Mexica, who would eventually give their name to all of Mexico.  Their leader Xolotl obtained legendary status as founder of the Aztec nation. In  painted codices, Xolotl is depicted as a skin-clad hunter leading his people from their ancestral home of Aztlan, from which we get the word "Aztec." The sign given by their god Huitzilopochtli for recognising their destined homeland  -- an eagle perched on a cactus with a snake in its beak -- later became the national symbol.