Disease and Conquistadors
The Inca Empire or Inka Empire[2] (Quechua: Tawantinsuyu[pronunciation?]) was the largest empire in pre-Columbian America.[3
The Inca empire was located in Peru. Sources: School and the South Park episode "Pandemic 2: The Startling". Yes, the episode was accurate :o)
Money and barbarians. Answer #2 Also, Diplomacy and marriage.
This is a major edit of the first answer which stated "2 seconds" The Inca Empire was "discovered" by the Spanish conquitadores. They were attracted to it as they and the Incas both valued gold. The empire in South America flourished for about 200 years and was ended by the Spanish conquests in the early 1500's. The Inca civilization spanded the western South American coastline.
The Inca empire included a diverse range of terrains such as mountains, valleys, deserts, tropical forests, and high-altitude plateaus. They utilized terrace farming and irrigation systems to adapt to these different environments and maximize agricultural productivity. This allowed them to sustain a large population and network of cities across their vast empire.
A Spanish conquistador named Hernando Cortes went to the Inca city of Tenochtitlan, in search of gold, but after hearing of how the Inca treated those who were conquered, Hernando marched strait into their city, taking their ruler, Montezuma 2, hostage, easily defeating the Inca's, because they had no horses, armor, or gunpowder.
Francisco Pizarro's second expedition involved setting sail from Spain in 1526 with the goal of conquering the Inca Empire in South America. After facing difficulties such as mutinies and harsh weather conditions, he eventually succeeded in establishing Spanish control over the Inca Empire in 1533 by capturing their ruler Atahualpa.
The Inca population was probably somewhere around 20 million, but historians believe it could have been as low as 2 million or as high as 37 million. Their empire was destroyed in 1533 when the Spanish attacked and brought the disease smallpox with them.
At its height, the Inca Empire covered approximately 2 million square kilometers (around 772,000 square miles). This vast territory included parts of modern-day Peru, Ecuador, Bolivia, Chile, and Argentina. The empire stretched along the western coast of South America, encompassing diverse geographical regions from the Andes mountains to coastal deserts.
Both empires were relatively the same size. They were, however, marginalized in Peru with the arrival of the colonial Spaniards. Some say for every 1 Inca, there were 2-3 Aztecs.
[1] The Inca Empire was known for its terracing of mountain slopes. One reason for terracing was increased farmland. The other was steepened slopes, against invaders. [2] A beautifully perfect example of terracing may be seen in Peru, at Machu Picchu, which means Old Peak. [We know the language of the Inca Empire as Quechua. But native speakers called it Runa Shimi, or Language of the people. The word Quechua actually is an insult. But the Empire's enemies considered the Inca thieves. And so that was the term that was passed on to the Spaniards, and to posterity.]
Fransisco Pizarro was a spaniyard that conqured the Inca empire, as you all know. He made 2 voyages. The second voyage was begun at 1526.