The causes for the Maya's decline are numerous, but one of the central causes is that the demands they placed upon their environment grew beyond the capacity of the land. At it's peak, there were about 15 million people occupying the Mayan world. Over-population of Mayan metropolises are suspected to have gone beyond levels that the Mayan political and social networks were able to support, resulting in social unrest and revolution. Frequent skirmishes by warring clans, such as the Toltec invasion of Chichen Itza, are suspected to have forced the Mayan populace to flee their cities. Recent studies have discovered evidenc