As indicated by Blanton's survey of the site, the Monte Albán hills appear to have been uninhabited prior to 500 BCE (the end of the Rosario ceramic phase).
At that time, San José Mogote was the major population center in the valley and base of a chiefdom that likely controlled much of the northern Etla branch.
Perhaps as many as three or four other, smaller chiefly centers controlled other sub-regions of the valley, including Tilcajete in the southern Valle Grande branch and Yegüih in the Tlacolula arm to the east.
Competition and warfare seem to have characterized the Rosario phase.
The regional survey data suggests the existence of an unoccupied buffer zone between the San José Mogote chiefdom and those to the south and east.

It is within this no-man's land that Monte Albán was founded at the end of the Rosario period  and it quickly reached a population estimate of around 5,200 by the end of the following Monte Albán Ia phase (ca.300 BCE).
This remarkable population increase was accompanied by an equally rapid decline at San José Mogote and neighbouring satellite sites, making it likely that its chiefly elites were directly involved in the founding of the future Zapotec capital.
This rapid shift in population and settlement, from dispersed localized settlements to a central urban site in a previously unsettled area, has been referred to as the “Monte Alban Synoikism” by Marcus and Flannery, in reference to similar recorded instances in the Mediterranean area in antiquity.

Although it was previously thought that a similar process of large-scale abandonment, and thus participation in the founding of Monte Albán, occurred at other major chiefly centers, such as Yegüih and Tilcajete, at least in the latter's case this now appears to be unlikely.
A recent project directed by Charles Spencer and Elsa Redmond of the American Museum of Natural History in New York has shown that, rather than being abandoned, the site grew significantly in population during the periods Monte Albán Early I and Late I (ca.
500-300 BCE and 300-100 BCE, respectively).
Tilcajete might have actively opposed incorporation into the increasingly powerful Monte Albán state.

By the beginning of the Terminal Formative (Monte Albán II phase, ca.
100 BCE-CE 200), Monte Albán had an estimated population of 17,200, making it one of the largest Mesoamerican cities at the time.
As its political power grew, Monte Albán expanded militarily, through cooption, and via outright colonization, into several areas outside the Valley of Oaxaca, including the Cañada de Cuicatlán to the north and the southern Ejutla and Sola de Vega valleys.(Feinman and Nicholas 1990) During this period and into the subsequent Early Classic (Monte Albán IIIA phase, ca.
CE 200-500), Monte Albán was the capital of a major regional polity that exerted a dominating influence over the Valley of Oaxaca and across much of the Oaxacan highlands.
Evidence at Monte Albán is suggestive of high-level contacts between the site's elites and those at the powerful central Mexican city of Teotihuacan, where archaeologists have identified a neighbourhood inhabited by ethnic Zapotecs from the valley of Oaxaca (Paddock 1983).
By the Late Classic (Monte Albán IIIB/IV, ca.
CE 500-1000), the site's influence outside and inside the valley declined.
Elites at several other centers, once part of the Monte Albán state, began to assert their autonomy, including sites such as Cuilapan and Zaachila in the Valle Grande and Lambityeco, Mitla, and El Palmillo in the eastern Tlacolula arm.
The latter is the focus of an ongoing project by Gary Feinman and Linda Nicholas of Chicago's Field Museum (Feinman and Nicholas 2002).
By the end of the same period (ca.
AD 900-1000), the ancient capital was largely abandoned.
The once powerful Monte Albán state was replaced by dozens of competing smaller polities, a situation that lasted up to the Spanish conquest.
As indicated by Blanton's survey of the site, the Monte Albán hills appear to have been uninhabited prior to 500 BCE (the end of the Rosario ceramic phase). At that time, San José Mogote was the major population center in the valley and base of a chiefdom that likely controlled much of the northern Etla branch. Perhaps as many as three or four other, smaller chiefly centers controlled other sub-regions of the valley, including Tilcajete in the southern Valle Grande branch and Yegüih in the Tlacolula arm to the east. Competition and warfare seem to have characterized the Rosario phase. The regional survey data suggests the existence of an unoccupied buffer zone between the San José Mogote chiefdom and those to the south and east.
It is within this no-man's land that Monte Albán was founded at the end of the Rosario period  and it quickly reached a population estimate of around 5,200 by the end of the following Monte Albán Ia phase (ca.300 BCE). This remarkable population increase was accompanied by an equally rapid decline at San José Mogote and neighbouring satellite sites, making it likely that its chiefly elites were directly involved in the founding of the future Zapotec capital. This rapid shift in population and settlement, from dispersed localized settlements to a central urban site in a previously unsettled area, has been referred to as the “Monte Alban Synoikism” by Marcus and Flannery, in reference to similar recorded instances in the Mediterranean area in antiquity.
Although it was previously thought that a similar process of large-scale abandonment, and thus participation in the founding of Monte Albán, occurred at other major chiefly centers, such as Yegüih and Tilcajete, at least in the latter's case this now appears to be unlikely. A recent project directed by Charles Spencer and Elsa Redmond of the American Museum of Natural History in New York has shown that, rather than being abandoned, the site grew significantly in population during the periods Monte Albán Early I and Late I (ca. 500-300 BCE and 300-100 BCE, respectively). Tilcajete might have actively opposed incorporation into the increasingly powerful Monte Albán state. 
By the beginning of the Terminal Formative (Monte Albán II phase, ca. 100 BCE-CE 200), Monte Albán had an estimated population of 17,200, making it one of the largest Mesoamerican cities at the time. As its political power grew, Monte Albán expanded militarily, through cooption, and via outright colonization, into several areas outside the Valley of Oaxaca, including the Cañada de Cuicatlán to the north and the southern Ejutla and Sola de Vega valleys.(Feinman and Nicholas 1990) During this period and into the subsequent Early Classic (Monte Albán IIIA phase, ca. CE 200-500), Monte Albán was the capital of a major regional polity that exerted a dominating influence over the Valley of Oaxaca and across much of the Oaxacan highlands. Evidence at Monte Albán is suggestive of high-level contacts between the site's elites and those at the powerful central Mexican city of Teotihuacan, where archaeologists have identified a neighbourhood inhabited by ethnic Zapotecs from the valley of Oaxaca (Paddock 1983). By the Late Classic (Monte Albán IIIB/IV, ca. CE 500-1000), the site's influence outside and inside the valley declined. Elites at several other centers, once part of the Monte Albán state, began to assert their autonomy, including sites such as Cuilapan and Zaachila in the Valle Grande and Lambityeco, Mitla, and El Palmillo in the eastern Tlacolula arm. The latter is the focus of an ongoing project by Gary Feinman and Linda Nicholas of Chicago's Field Museum (Feinman and Nicholas 2002). By the end of the same period (ca. AD 900-1000), the ancient capital was largely abandoned. The once powerful Monte Albán state was replaced by dozens of competing smaller polities, a situation that lasted up to the Spanish conquest.
Monte Albán