1. Hernán Cortés: He led an expedition that resulted in the Spanish conquest of the Aztec Empire in Mexico in the early 16th century.
2. Francisco Pizarro: He conquered the Inca Empire in present-day Peru in the 1530s.
3. Vasco Núñez de Balboa: He was the first European to discover the Pacific Ocean from the American mainland in 1513.
4. Juan Ponce de León: He explored Florida in 1513, becoming the first European to set foot on mainland North America.
5. Álvar Núñez Cabeza de Vaca: He explored the southwestern United States and Mexico in the 1530s.
6. Hernando de Soto: He explored the southeastern United States in the 1540s.
7. Francisco Vásquez de Coronado: He explored the southwestern United States in the 1540s.
These conquistadors and their expeditions played a pivotal role in establishing Spain's colonial empire in the Americas, which would shape the history and development of the region for centuries to come.