Question

What happened when the Aztec and Spanish fought?

Answer 1

Briefly: between 1519 and 1521 Hernán Cortés and a small force of Spaniards, together with thousands of indigenous allies, overthrew the Aztec Empire centered at Tenochtitlan. The conquest combined military actions, alliances with enemies of the Aztecs, superior European weapons and ships, and especially epidemic disease (smallpox), and it resulted in the collapse of the Aztec state and the start of Spanish colonial rule in central Mexico.

Key events
- 1519: Cortés arrives on the Gulf coast, meets and takes on indigenous allies (notably the Tlaxcalans and some Gulf coast peoples) who hated Aztec domination.
- November 1519: Cortés enters Tenochtitlan and is received by Emperor Moctezuma II. The Spaniards soon hold Moctezuma effectively hostage.
- May 1520: While Cortés is away dealing with reinforcements and politics, a massacre of Aztec nobles by a Spanish lieutenant (Pedro de Alvarado) at a festival sparks outrage and an uprising in the city.
- June 30, 1520 — “La Noche Triste”: the Spaniards attempt to escape Tenochtitlan and suffer heavy losses as the Aztecs attack them leaving the city.
- 1520–1521: Smallpox and other European diseases strike the native population, killing large numbers (including many leaders) and weakening Aztec resistance.
- Spring–summer 1521: Cortés returns with reinforcements and allied indigenous forces, builds brigantines to control the lake, besieges Tenochtitlan, cutting off food and water. After weeks of fighting, Tenochtitlan falls on August 13, 1521. The last emperor, Cuauhtémoc, is captured.

Why the Spanish won
- Indigenous allies: many peoples subject to Aztec tribute joined the Spaniards to overthrow Aztec domination.
- Disease: smallpox devastated the Aztec population and leadership, greatly reducing their ability to resist.
- Military advantages and tactics: horses, firearms, steel weapons, artillery, ships on the lake, and siege tactics helped the Spaniards and their allies.
- Political divisions: internal rivalries and resentments within the Aztec empire undermined unified resistance.

Consequences
- The Aztec political system collapsed; Tenochtitlan was destroyed and replaced by Mexico City, the capital of New Spain.
- Spanish colonial institutions (missionaries, encomienda labor systems, Spanish law and language) were imposed; Christianity spread.
- Massive demographic decline of indigenous peoples over the following decades, mostly from disease but also from warfare and exploitation.
- Cultural blending and long-lasting social, economic, and political changes across the region.

If you want, I can give a shorter timeline, more on the role of smallpox, biographies of Cortés or Cuauhtémoc, or primary-source perspectives from both sides.