Two things set off the Early from the Late Classic: first, the strong Izapan element still discernible in Early Classic Maya culture, and secondly, the appearance in the middle part of the Early Classic of powerful waves of influence, and almost certainly invaders themselves, from the site of Teotihuacan in central Mexico. This city was founded in the first century BC in a small but fertile valley opening onto the northeast side of the Valley of Mexico. On the eve of its destruction at the hands