The city was thought to have been established around 100 BCE and continued to be built until about 250 CE . The city may have lasted until sometime between the 7th and 8th centuries CE. At its zenith, perhaps in the first half of the 1st millennium CE, Teotihuacan was the largest city in the pre-Columbian Americas. At this time it may have had more than 200,000 inhabitants, placing it among the largest cities of the world in this period.