Tikal was one of the most powerful Maya city-states, flourishing between c. 200–900 AD with a population of perhaps 100,000. Temple IV (c. 741 AD) rises 65 meters. Tikal's growth correlates with the arrival of a ruler named Siyaj K'ak' in 378 AD, linked to Teotihuacan influence — a documented historical event, not alien contact. The city's decline in the 9th century was part of the broader Maya Classic collapse driven by drought and political fragmentation.