The Incas were defeated by the European invaders , mostly because they had no immunity to European diseases.
Explanation:
Europeans brought with them germs and viruses that were not present in the environment where the Inca civilization lived. For that reason, the Incas had no immunity to the diseases they caused. As a matter of fact, the Incas were hit by an epidemic of diseases, which incapacitated them and greatly contributed to their defeat. Smallpox and influenza were the main cause of death, but other diseases were also spread, such as typhus, chicken pox, and measles.
