What events led to open conflict between the Aztecs and the conquistadors?

Answer 1

Basically, it was Spanish greed. The Spanish King Charles V got to hear rumours of the mythical land of 'El Dorado', a legendary Aztec city that was said to be filled with vast amounts of gold and other treasure. The Spanish Government was also aware that apart from this, there was genuine evidence that Central and South America really were highly rich in precious minerals and gemstones. The Aztecs tried to explain to the Conquistadors that El Dorado was only a folk tale, and that it was not real, but the Spanish disbelieved them and thought that they were lying, to cover up the place for themselves. In the end, the Spaniards decided that conquest of what is now Latin America in order to gain control of it's material riches was worth more than retaining friendly relations with the Aztec civilisation, so began a complex system of conquering the Inca civilisation using the technique of 'divide and rule'. The Aztec and Inca world was not by any means united- there was civil war and conflict between the kingdoms and peoples of the region quite apart from any intervention from Europe. The Spanish used this to their own advantage, making alliances of convenience with certain kingdoms and fiefdoms to increase their military might in the overthrowing of other parts of the region, and also deliberately setting tribes and Aztec noble houses against each other, so that they would go to war and thus deplete their military strength, making them unable to resist the Spanish conquerors. In some cases the Spanish deliberately courted the alliegance of some Aztec kingdoms in order to make them 'puppet states' of the Conquistadors, only being allowed autonomy and to continue ruling themselves if they retained regional stability on Spain's behalf and offered military support to the Spanish whenever this was demanded.