The Aztec Empire flourished between c. 1345 and 1521 CE and, at its greatest extent, covered most of northern Mesoamerica. Aztec warriors were able to dominate their neighbouring states and permit rulers such as Motecuhzoma II to impose Aztec ideals and religion across Mexico. Highly accomplished in agriculture and trade, the last of the great Mesoamerican civilizations was also noted for its art and architecture which ranks amongst the finest ever produced on the continent. The Aztec state is actually the most well documented Mesoamerican civilization with sources including archaeology, native books (codices) and lengthy and detailed accounts from their Spanish conquerors - both by military men and Christian clergy. Historical Overview Sometime around 1100 CE the city-states or altepetl which were spread over central Mexico began to compete with each other for local resources and regional dominance. Tenochtitlán Religion The sun, not surprisingly, had great significance for the Aztecs.