Conquistador is the term used to refer to the soldiers, explorers, and adventurers who achieved the Conquista, i.e. brought much of the Americas and Asia Pacific under Spanish colonial rule between the 15th and 17th centuries. The Genoese Columbus's discovery of the New World in 1492 afforded Spain a head start in Colonization of the Americas, i.e. North, South America, continental Central and the Caribbean regions; the whole area was designated the West Indies, as the explorers originally presumed they had reached the Atlantic coast of the Asia-Pacific Far East, which was being reached and soon colonized as 'East Indies', notably the archipelago of the Philippines and Guam. 

Background 

The leaders of Spanish expeditions to the New World called themselves conquistadors, a name expressing the similarity to the recently accomplished reconquista, the Christian crusades to (re)conquer the Iberian Peninsula from the Muslim Moors (711-1492). They also evoked the name of Santiago Matamoros ("St. James the Moor-killer") before going into battle against the pagan Native population of the Americas, who were considered righless as long as not converted to Catholicism, so their lands were annexed as terra nullius with papal blessing, the only rival claim to be taken seriously was that of the Portuguese, settled after papal arbitration in the treaty of Tordesillas in 1494. Many conquistadors were poor, including some nobles (hidalgos) seeking a fortune in the West Indies, since there were limited prospects in Europe, as previously in crusades in the Old World. Many were also fleeing the religious repression caused by the Spanish Inquisition. 

History 

New World 

The first Spanish conquest in the Americas was the island of Hispaniola (presently shared by Haiti and the Dominican Republic). From there, Juan Ponce de Leon conquered Puerto Rico and Diego Velasquez took Cuba. The first settlement on the mainland was Darien in Panama, settled by Vasco Nunez de Balboa in 1512. As these Caribbean regions proved no great treasury or endless supply of priceless spices, the 'disappointment' motivated further exploration. 

The first immensely successful Conquistador was Hernán Cortez. Between 1520 and 1521, Cortez, along with some Native American allies, conquered the mighty Aztec empire, thus bringing present day Mexico (then called New Spain) under the dominion of the Spanish empire. Of comparable importance was the conquest of the South American Inca Empire by Francisco Pizarro. Both were helped by extraordinarily convenient native myths predicting a messianic god would come from the very direction they approached from (Cortez the east, Pizarro the west), their exotic appearance and apparently magical possession of horses and fire arms seemingly confirming their divine nature. In each case the emperor was quickly captured, and major revolts would not break out until reinforcements from Europe had arrived. Smallpox and other European plagues wiped out most of the native population and the military and political leaders. 

Rumors of golden cities (Cibola in North America and "El Dorado" in South America) caused several more expeditions to leave for the Americas, but many returned without finding any gold, finding less gold than expected, or finding Fool's Gold. The ransom that Sapa Inca Atahualpa paid for his freedom was taken back to Spain, leading to additional Conquistador expeditions in South America and the Pacific. 

Amazingly, the greedy misrule of the Spaniards and the unwise use of the crown's share of the colonial proceeds would manage not to see the Hapsburg empire grow and prosper into the world's greatest ever, but to bankrupt the state repeatedly while the influx of precious metal caused towering inflation in Europe, to largely lose the war against Protestantism, to weaken the domestic economy, and ultimately to see the colonial prominence shifting to rivals, the British and their US offshoot coming out on top and helping the Creoles to achieve early independence from Spain in the 19th century.