Short answers, pulled from the story.
The Zapotec civilization began forming in the late 6th century BC when three distinct societies occupied the Y-shaped Central Valleys of Oaxaca. Archaeological evidence from this era shows burned temples and sacrificed war captives indicating fierce competition between these groups.
People who left San José Mogote populated the new settlement that became known as Monte Albán during the Rosario phase which spanned from 700 to 500 BC. Walls and fortifications appeared around the site during the Monte Alban 2 phase lasting roughly from 100 BC to 200 AD in response to military threats.
Ms. Romero documented a population decline from 1.5 million people in 1520 to just 150,000 by 1650 due to nineteen major epidemics including smallpox and typhoid. Despite these catastrophic losses the population of Oaxaca rebounded significantly over time.
Today there are seven distinct Zapotec languages and over 100 dialects spoken across Northern Sierra Central Valleys Southern Sierra Isthmus of Tehuantepec and Pacific Coast. Migration has spread speakers into Mexico City and Los Angeles CA while the language functions as a tone system with up to four distinct tonemes.
The region was conquered by the Aztecs in 1458 and they established a fort on the hill of Huaxyácac now called El Fortín in 1486. This fort enforced collection of tribute payments throughout Oaxaca until the last battle between Aztecs and Zapotecs occurred between 1497 and 1502 under ruler Ahuizotl.