The Maya originated around 3,000 years ago in present-day Honduras, Mexico, Guatemala, and Belize. From around AD 250 to AD 900, the Mayan empire flourished in the southern regions. Around AD 900, the empire in the south collapsed. No one knows why. Scholars have suggested, among other reasons, political upheaval, drought, disease, or overpopulation. But while the empire in the south waned, that in the north, especially in the Yucatan, flourished until the Spanish conquests of the sixteenth century.