1) In the late 15th century, Ferdinand II of Aragon and Isabella I of Castile unified Spain through marriage, establishing rule as the "Catholic Monarchs."
2) Under their rule, Spain reconquered territory from the Moors, expelled Jews and Muslims, and financed Christopher Columbus' voyage, establishing Spain as the first global empire.
3) Spanish conquistadors then conquered the Aztec, Inca, and Maya civilizations in the Americas, claiming large territories and importing diseases that devastated indigenous populations. The influx of silver from the Americas funded Spain's powerful military.