While much work has been done at the popular tourist destination of Uxmal to consolidate and restore buildings, little in the way of serious archeological excavation and research has been done; therefore, the city's dates of occupation are unknown and the estimated population (about 15,000 people) is at present only a very rough guess subject to change upon better data. Most of the city's major construction took place while Uxmal was the capital of a Late Classic Maya state around 850-925 AD, though after about 1000 AD, Toltec invaders took over and most building ceased by 1100 AD.
Maya chronicles say that Uxmal was founded about 500 A.D. by Hun Uitzil Chac Tutul Xiu. For generations Uxmal was ruled over by the Xiu family, was the most powerful site in western Yucat�n, and for a while in alliance with Chichen Itza dominated all of the northern Maya area. Sometime after about 1200 no new major construction seems to have been made at Uxmal, possibly related to the fall of Uxmal's ally Chichen Itza and the shift of power in Yucat�n toMayapan. The Xiu moved their capital to Man�, and the population of Uxmal declined.
Uxmal was dominant from 875 to 900 CE. The site appears to have been the capital of a regional state in the Puuc region from 850-950 CE. The Maya dynasty expanded their dominion over their neighbors. This prominence didn't last long. Population dispersed around 1000 CE.
After the Spanish conquest of Yucat�n (in which the Xiu allied themselves with the Spanish), early colonial documents suggest that Uxmal was still an inhabited place of some importance into the 1550s, but no Spanish town was built here and Uxmal was soon after largely abandoned
