Many reasons can be offered for the fall of the Incas, but the sudden conquest of a mighty empire by only a handful of
Spaniards is still hard to comprehend. The Indian empires of Central Mexico had already succumbed to the Spaniards, who
under Hernán Cortes had invaded Mexico in 1519. However, the Incas were unaware of such events, inasmuch as there was
no direct contact of Aztec and Maya with Inca. The white man's presence became known only in 1523 or 1525, when a
Spaniard named Alejo Garcia led an attack with Chiriguano Indians on an Inca outpost in the Gran Chaco, a dry lowland to the
southeast of the Inca realm. In 1527 Francisco Pizarro appeared briefly at Tumbes on the northwest Peruvian coast and then
sailed away, leaving behind two of his men. Shortly afterward, Ecuador was devastated by a pestilence (possibly smallpox)
brought by one of them.