The Aztec Empire arose in the early 15th century and appeared to be on a path to asserting a dominance over the Valley of Mexico region not seen since Teotihuacan , when Mesoamerica was discovered by Spain and conquered by the conquistadores and a large number of native allies .
The Aztec Empire rises in the early 15th century and seems on the path to gain a dominance over the whole region not seen since Teotihuacan , when Mesoamerica is discovered by Spain and conquered by the Conquistadores .