1. The purpose of the conquistadors was to conquer the ancient empires in the region of Central and South America. The first Spaniards who came to New World were the conquistadors, mercenaries, and soldiers who came for adventure as well as to make quick fortunes. The reason for the establish colonies in the New World was the glory, gold and God. Spanish invading the early empire and taking control over them by showing their glory, spreading Christianity became their reason for converting the Natives. Gold (silver) became their source for generating wealth in the New World.
2. The conquistadors were successful in colonizing Central America through invading the Maya Civilization. Mayan People were unable to defend themselves because of the spread of the diseases which killed somewhat the entire civilization who were not immune to it. Spanish weapons were superior to the Mayan who used bow and arrow, spears etc.
3. Hernan Cortes defeated the Aztecs in 1521 and claimed Mexico for Spain.
4. Central America countries speak Spanish because of the Spain occupation in the region by establishing colonies after the discovery of America in 1492.