Although several theories of the origin of the Zapotec peoples exist, including some possibly influenced in the post-conquest period, scholars largely agree the Zapotecs inhabited the Central Valley of Oaxaca as early as 500–300 BCE, during what is considered the Monte Alban I period. During this period, the Zapotecs established a significant system of governance over the population of the region. The Monte Alban periods, of which five have been categorized, lasted from 500 BCE to the time of conquest in 1521 AD. Yet archaeological evidence from the site of Monte Alban, "the first city in ancient Mesoamerica"[3] has revealed settlement of the region as far back as 1150 BCE. Scholars have been able to correlate with the Formative, Classic, and post-Classic periods of civilization in the region within the greater Mesoamerican history through these discoveries. The Formative stage, from about 500 BCE to 200 AD of which the periods of Monte Alban I and II are attributed to, is characterized by a shift to sedentary settlements and the practice of agriculture for subsistence.