The Spanish were called conquistadors because they were the ones who conquered the Americas. The word conquistador comes from the Spanish verb "conquistar", which means "to conquer". The conquistadors were a group of explorers, soldiers, and adventurers who came to the Americas in search of wealth, glory, and power. They were often motivated by religious zeal and a desire to spread Christianity. The conquistadors were also known for their brutality and violence, and they often used force and coercion to conquer the indigenous peoples of the Americas.