Short answers, pulled from the story.
The Aztecs founded the city of Tenochtitlan in the year 1325. They established the settlement on a swampy island in the middle of Lake Texcoco after following a vision of an eagle perched on a prickly pear cactus devouring a snake.
The Mexica were the specific name for the Aztec people who formed the Triple Alliance in 1427. This alliance united the Mexica with the city-states of Texcoco and Tlacopan to overthrow the Tepanec empire and establish Tenochtitlan as the dominant power.
The Aztecs fought the Flower Wars to capture prisoners for sacrifice rather than to conquer territory. These ritualized conflicts served as a training ground for warriors and maintained the empire's military machine while keeping rival city-states like Tlaxcala and Huexotzinco in check.
Historical accounts suggest that over 80,000 prisoners were sacrificed during the four-day inauguration of the Great Temple in 1487 under the ruler Ahuitzotl. Modern estimates suggest the actual number was likely in the thousands.
The Spanish captured the last Aztec ruler Cuauhtémoc on the 13th of August 1521, marking the end of the Aztec Empire. Hernán Cortés led the conquest with fewer than 600 men and forged alliances with the Aztecs' enemies to destroy Tenochtitlan.