Maya beginnings go back at least 4000 years in southern Mexico and Central America. The Maya of the tropical lowlands were one of several linguistically distinct groups who occupied pre-Columbian Mesoamerica. Their complex social order and civilization, which arose from early village farming, encompassed remarkable achievements in architecture, the arts, and hieroglyphic writing. Their Classic civilization (A.D. 250 to 1000) was a tightly integrated system in which subsistence, technology, settlement, the arts, and ideology closely intermeshed. Their decline and the subsequent Postclassic Period (A.D. 1000 to .1520), the continuing subjects of debate among Mayanists, are perhaps best understood in the light of more widespread Mesoamerican trends and changes.