Settlement of Cholula began between 500 and 200 BCE (middle Pre Classic period), with two small villages established near water sources in what is now the eastern side of the city. They were two of a number of agricultural villages with ceremonial centers in the area, with evidence of emerging social stratification. Its earliest settlers were probably speakers of Oto-Manguean languages, linguist Terrence Kaufman has proposed that they were speakers of the Chorotega language of the Mangue branch of the oto-mangue family. The various small rivers and streams allowed for irrigated agriculture and at one time, several converged into a shallow lake, which may have been used for chinampas. At the end of the Pre-classic, many other settlements in the area were abandoned but Cholula grew, possibly with migration from these other settlements. This made Cholula the dominant political force in the region. This was also the time when work on the Great Pyramid began, along with another monument called the Edificio Rojo. Cholula continued to grow during the Classic period (200 – 800 CE) to an extension of over and a population of between 20,000 and 25,000. It also remained dominant over the Puebla-Tlaxcala region, with more monumental construction, including the addition of two stages to the Great Pyramid.