How did the introduction of diseases by the Europeans affect the Spanish conquest of the Aztec?

Indigenous Americans had not been exposed to the diseases before and their immune systems could not tolerate the illnesses, benefiting the Spanish forces.
Although diseases weakened forces on both sides considerably, deaths from illness were few.
After Aztec forces were weakened by disease, they joined with the Totonac and Tlaxcalans to fight against the Spaniards.
The spread of disease slowed the progression of battles between the Spaniards and the Aztec.

The introduction of diseases by the Europeans had a significant impact on the Spanish conquest of the Aztec. The indigenous Americans, including the Aztecs, had never encountered these diseases before, which meant that their immune systems were not equipped to resist them. This resulted in widespread outbreaks of diseases, such as smallpox, measles, and typhus, among the Native American population.

The diseases caused high mortality rates among the Aztecs, weakening their forces considerably. The Spanish conquistadors, on the other hand, had already been exposed to these diseases in Europe and had developed some level of immunity to them. This gave the Spanish forces an advantage, as they were less affected by the diseases and could continue their military campaigns.

However, it is important to note that diseases also affected the Spanish forces, albeit to a lesser extent. The Spaniards, although immune to some extent, still suffered casualties from these diseases. This resulted in a significant decrease in the overall manpower of both sides, but the impact on the Native Americans was far more severe due to their lack of immunity.

The weakened state of the Aztec forces, combined with their loss of many experienced warriors to illness, prompted them to seek alliances with other indigenous groups, such as the Totonac and Tlaxcalans, to fight against the Spaniards. The Aztecs and their allies hoped that their combined forces would be sufficient to repel the Spanish conquest.

Additionally, the spread of diseases also had an indirect effect on the progression of battles between the Spaniards and the Aztecs. As the diseases ravaged the indigenous population, it slowed down the pace of military engagements. The Aztecs were preoccupied with trying to contain and cope with the spread of diseases within their population, diverting their attention and resources away from the ongoing conflicts.

In summary, the introduction of diseases by the Europeans severely affected the Spanish conquest of the Aztec. The lack of immunity among the indigenous population resulted in a high mortality rate, weakening the Aztec forces. This, in turn, led to alliances being formed between the Aztecs and other indigenous groups, and also slowed down the progression of battles between the Spaniards and the Aztecs.