Cuilapan de Guerrero is a town and municipality located in the central valley region of Oaxaca in southern Mexico. It is 10 kilometres (6.2 mi) to the south of the capital city of Oaxaca on the road leading to Villa de Zaachila, and is in the Centro District in the Valles Centrales region.
Cuilapan, originally called Sahayuca, has been a permanent settlement since at least 500 BCE. It developed into a city state but was absorbed by Monte Alban until between 600 and 900 CE. After this, Cuilapan returned to being an independent city-state, equal to a number of other important city states in the area. After the Spanish conquest, Cuilapan had a population of over 40,000 people with formidable social, economic and cultural institutions.
The Cuilapan area has been settled by humans since 1500 BCE with a sedentary village established by 500 BCE. These sedentary peoples developed activities such as weaving, pottery and stonemasonry, with permanent houses, ceremonial structures and tombs. The society here grew and stratified over time and eventually a simple writing system came into existence.
Cuilapan developed as an independent city state until the rise of Monte Alban, which came into dominance because it provided a refuge in a defensible location. During this time, Cuilapan was one of the satellite cities of the dominion. Between 600 and 900 CE, Monte Alban decline and collapsed, allowing Cuilapan and others to become independent again.