The conquest of the Aztec and Incan empires were relatively easy battles. A couple of reasons as to why it was so easy were because these empires were isolated, they knew nothing of the new world and other cultures, they believed that the Europeans intentions were of no relevance to them and underestimated them. Another reason was technology. Technology was a huge part in the conquest of these empires Indian war tactics were old and out dated. They were no match for the Spanish and their cannons, crossbows, swords, armor, shields, and the hand held musket.
The poor judgment of the Aztec people was their main downfall. The timing of the Europeans arriving towards the end of the fall where harvesting was a main priority of the Aztecs and not warfare this led to the underestimation of the Europeans and their goals.
The Incans were completely isolated, they had no contact with other cultures, and they instead believed that the arrival of the Europeans was part of an old Inca legend and that they intended no trouble.
The beliefs and lack of knowledge gave the Europeans a head start on planning their strategies for overthrowing the civilizations. If the cultures had taken prompt action it would have been unlikely that the European cultures would have been so successful and taken over the empires as easily as they