It was rising from being a village to being a city of some importance. Cholula was founded by the Toltecs sometime round 1500 BC. For Toltecs the city was a place for commerce, worship and burial.
It has been continuously occupied and has been a major religious center. The Great Pyramid, Tlachihualtepetl, is the largest pre-Hispanic structure in The World in the terms of volume of construction material. As the city became a place of power, many of the powerful cultures of Mexico had their turn to rule it - the Olmecs, Toltecs, and later the Aztecs, with whom the city had some alliance.
For centuries, Cholula was considered to be the Tollan or Place of the Tules, from which the various groups of origin had been expelled and to where they return (Cholollan-Tollan).
By the time Cortes passed through Mexico and through Cholula in 1519, the town was already old and fairly large.
Ancient city of Cholula