Atahualpa in the context of "Battle of Cajamarca"

The Incas were most notable for establishing the Inca Empire which was centered in modern-day Peru and Chile. It was about 4,000 kilometres (2,500 mi) from the northern to southern tip. The Inca Empire lasted from 1438 to 1533. It was the largest Empire in America throughout the Pre-Columbian era. The Inca state was originally founded by Manco Cápac in the early 1200s, and is known as the Kingdom of Cuzco. Under subsequent rulers, through strategic alliances and conquests, it expanded beyond Cusco and into the Sacred Valley. Their territory then rapidly grew under the 9th Sapa Inca (emperor), Pachacuti and his descendents.

Over the course of the Inca Empire, the Inca used conquest and peaceful assimilation to incorporate the territory of modern-day Peru, followed by a large portion of western South America, into their empire, centered on the Andean mountain range. However, shortly after the Inca Civil War, the last Sapa Inca of the Inca Empire, Atahualpa, was captured and killed on the orders of the conquistador Francisco Pizarro, marking the beginning of Spanish rule. The remnants of the empire retreated to the remote jungles of Vilcabamba and established the small Neo-Inca State, which was conquered by the Spanish in 1572.

The Spanish conquest of the Inca Empire, also known as the Conquest of Peru, was one of the most important campaigns in the Spanish colonization of the Americas. After years of preliminary exploration and military skirmishes, 168 Spanish soldiers under conquistador Francisco Pizarro, along with his brothers in arms and their indigenous allies, captured the last Sapa Inca, Atahualpa, at the Battle of Cajamarca in 1532. It was the first step in a long campaign that took decades of fighting but ended in Spanish victory in 1572 and colonization of the region as the Viceroyalty of Peru. The conquest of the Inca Empire (called "Tahuantinsuyu" or "Tawantinsuyu" in Quechua, meaning "Realm of the Four Parts"), led to spin-off campaigns into present-day Chile and Colombia, as well as expeditions to the Amazon Basin and surrounding rainforest.

When the Spanish arrived at the borders of the Inca Empire in 1528, it spanned a considerable area and was by far the largest of the four grand pre-Columbian civilizations. Extending southward from the Ancomayo, which is now known as the Patía River, in southern present-day Colombia to the Maule River in what would later be known as Chile, and eastward from the Pacific Ocean to the edge of the Amazonian jungles, it covered some of the most mountainous terrains on Earth. In less than a century, the Inca had expanded their empire from about 400,000 km (150,000 sq mi) in 1448 to 1,800,000 km (690,000 sq mi) in 1528, just before the arrival of the Spanish. This vast area of land varied greatly in culture and climate. Because of the diverse cultures and geography, the Inca allowed many areas of the empire to be governed under the control of local leaders, who were watched and monitored by Inca officials. Under the administrative mechanisms established by the Inca, all parts of the empire answered to, and were ultimately under the direct control of, the Inca Emperor. Scholars estimate that the population of the Inca Empire was between 12 and 16 million.

The Inca society was the society of the Inca civilization in Peru. The Inca Empire, which lasted from 1438 to 1533 A.D., represented the height of this civilization. The Inca state was known as the Kingdom of Cusco before 1438. Over the course of the empire, the rulers used conquest and peaceful assimilation to incorporate a large portion of western South America, centered on the Andes mountain ranges. The empire proved relatively short-lived however: by 1533, Atahualpa, the last Sapa Inca (emperor) of the Inca Empire, was killed on the orders of the conquistador Francisco Pizarro, marking the beginning of Spanish rule. The last Inca stronghold, the Neo-Inca State in Vilcabamba, was conquered by the Spanish in 1572.

The Inca Civil War, also known as the Inca Dynastic War, the Inca War of Succession, or, sometimes, the War of the Two Brothers, was fought between half-brothers Huáscar and Atahualpa, sons of Huayna Capac, over succession to the throne of the Inca Empire. The war followed Huayna Capac's death.

It began in 1529, and lasted until 1532. Huáscar initiated the war; appointed as emperor and claiming the throne, he wanted to defeat Atahualpa's competition. Atahualpa was tactically superior to his brother in warcraft and to the mighty armies of Cusco, which their father had stationed in the north part of the empire during the military campaign. Accounts from sources all vary in the exact details.