Atahualpa was the the youngest son of Huayna Capac. This would mean that Atahualpa was not the heir to the Incan throne. This would cause the empire to break into a civil war once Huayna died. On one side, Atahaulpa (who at the time had the military's favor) against Huascar.
This great war spread all throughout the empire. This would cause the Incan economy to start to crash. The war waged on for years.
Atahualpa would end up winning the war. He then would sentence his opponent and his family to death.
Then, the Spanish came. The Inca thought them of white gods and didn't think to put up arms so the Spanish planed to ambush them.
The Spanish were able to capture Atahualpa. He then gave them a bounty of gold for his freedom. This would be one of the largest ransoms of all time
The Spanish ended up taking the gold, but also Atahualpa's life. This would end the Incan cempire.