Final answer:
The Spanish conquistadors sought gold and power by exploring and claiming new lands, often with brutal consequences for the indigenous peoples. Their conquests and colonization efforts were driven by personal gain and the desire to expand the Spanish empire, using the encomienda system to assert control over the land and its inhabitants.
Step-by-step explanation:
Based on the evidence provided, we can draw the conclusion that the Spanish conquistadors were primarily motivated by the pursuit of wealth and power in their explorations of South and Central America. This is illustrated by their relentless search for lands containing purported gold, as seen in the expeditions of Hernán Cortés and others. Additionally, the Spanish had a policy of claiming the lands they explored for Spain, demonstrated by actions such as Balboa's claim over the Pacific Ocean and Cortés's conquest of the Aztec Empire, which aimed to secure riches and territory for the Spanish crown.
The conquests also had severe consequences for the native populations, including the spread of diseases brought by the Europeans, the destruction of established civilizations, and the forceful imposition of Christianity. Furthermore, their efforts were part of a larger pattern of colonization and the establishment of the encomienda system that significantly altered the social, political, and economic landscapes of the Americas.