"Who were the Teotihuacános" is one of those vexing questions that so far the available evidence hasn't been able to provide a concrete answer too - only theories. Some more wild and wonderful than others *grins at Sak*.

According to Spanish chroniclers, the Totonacs claimed to have built Teotihuacán (they certainly had a quarter there). The Aztecs, who had no historical context for it, said the Toltecs or the gods built it, and for many years archaeologists believed them (about the Toltecs, I mean, not the gods...). Mind you, the Aztecs didn't always mean the same thing as we do nowdays by "Toltec", which rather muddles the issue. If it was the Toltecs, it would at least go some way towards explaining the many religious and cultural themes that Teotihuacán, the Toltecs and Aztecs shared - such as the worship of Quetzalcoatl and Tlaloc. However, the main problem with accepting the Toltecs as the founders of Teotihuacán has always been the dates - the Toltec civilization came after Teotihuacán. There are some Olmec influences in the architecture and culture of Teotihuacán, but I don't think (?) anyone's seriously suggested they founded the city. Other contenders are the Otomi of central Mexico or Popolocan of Oaxaca.

Okay, so let's consider Sak's theory - and I don't think the idea that no single culture was the point of origin is actually too way out in left field LOL. There was a lot of cross-cultural contact and influence going on around 200 BCE when Teotihuacán's first buildings were going up, and a hell of a lot more people milling around (a survey of the Valley of Mexico showed that by the end of the Early Classic period there were 40 times as many people living in the area than in the Middle Preclassic*). The Zapotec city of Monte Albán was flourishing, Cholula was building its Great Pyramid around the same time Teotihuacan was building its own, down on the Gulf Coast new civilizations were appearing that show continuity from the Olmecs, such as Classic Veracruz, and there were Maya influences sneaking in here and there. I haven't run across any mention of Teotihuacan engaging in military ventures against any of the Valley of Mexico/Oaxaca Valley cultures - in fact, as I just posted elsewhere, relations with Monte Albán at least seem to have been friendly.

The main argument against Teotihuacán being the 'melting pot' of multiple cultures I can see is that, although it was a multi-ethnic city, it had a very distinctive culture and icongraphic style that is more influential than influenced by anything else, if you see what I mean?

In other words - the jury's still out LOL

[* Mexico from the Olmecs to the Aztecs, Coe & Koontz]