What may have caused the Incans to be defeated so easily by the Spanish? They did not have enough people to fight against the Spanish. They were a peaceful people that were not accustomed to fighting. They were having a civil war when the Spanish arrived. They did not have enough food to support their people.

The primary reason the Incans were defeated so easily by the Spanish was that they were having a civil war when the Spanish arrived. The Incan Empire was weakened by internal conflict, specifically a civil war between two brothers, Atahualpa and Huáscar, who were vying for the throne. This division made it easier for the Spanish, led by Francisco Pizarro, to conquer the empire. Additionally, other factors such as the superior weaponry of the Spanish, the spread of diseases like smallpox, and strategic alliances with local tribes also contributed to the rapid defeat of the Incans.