Top Inca military campaigns that built the empire
The Inca Empire of Tawantinsuyu was built in less than a century through a series of major military campaigns carried out under the emperors Pachacuti (r. c. 1438–1471), Túpac Inca Yupanqui (r. c. 1471–1493), and Huayna Capac (r. c. 1493–1527). These campaigns absorbed a wide range of polities — from the small highland kingdoms of the Cusco basin to the great coastal states such as the Chimú of the north coast, and from the tropical lowlands of Ecuador to the arid deserts of northern Chile. They were not isolated raids but sustained operations of imperial conquest, typically involving the mobilization of tens of thousands of soldiers, carefully planned logistics, and the integration of conquered territory through forced resettlement, the installation of Inca governors, and the extension of the state road system. Understanding these campaigns is essential to understanding the rise of the Inca Empire and its final form on the eve of the Spanish arrival.
The principal sources for Inca military history are the sixteenth-century chronicles, especially those of Pedro Cieza de León, Pedro Sarmiento de Gamboa, Juan de Betanzos, and Miguel Cabello de Balboa, all of whom drew on the testimony of Inca nobles and Spanish witnesses, supplemented by a substantial body of archaeological evidence — fortifications, road segments, garrison towns, and the residue of battles and sieges — accumulated since the early twentieth century.
The Chanka War and the Foundations of Imperial Power
The campaign that opened the imperial age was the war against the Chanka, a powerful highland kingdom centered on the Andahuaylas region west of Cusco. The traditional account, recorded in detail by Sarmiento de Gamboa, places the climax of the war in 1438, when a Chanka army invaded the Cusco valley and threatened the Inca capital. The Inca ruler Viracocha is said to have fled, and the defense of the city was led by his son, the young prince Cusi Yupanqui, who rallied the defenders and won a decisive battle at the gates of Cusco. The victory was understood in the official tradition as a divine sanction for Cusi Yupanqui’s subsequent accession as the emperor Pachacuti.
The Chanka war established the military credibility of the new Inca regime and gave it a base from which to organize further conquests. The Chanka kingdom was incorporated into the empire, and its peoples were resettled in distant parts of the empire as mitma colonists. The campaign also produced the institutional reforms — the standing army, the standardized mit’a labor draft, and the provincial administration — that made the subsequent expansion of the empire possible.
The Conquest of the Central Highlands
Between about 1440 and 1460, the Incas absorbed the remaining polities of the central Andean highlands. The principal targets were the Quechua kingdoms of the Apurímac valley, the small states of the Cusco basin’s eastern and western margins, and the Colla and Lupaca polities of the Lake Titicaca basin. Each of these campaigns involved a combination of military pressure and negotiated submission, and the chronicles record numerous cases in which local leaders accepted Inca rule in exchange for confirmation of their local authority. The pattern of negotiated incorporation became a standard feature of Inca expansion, and it allowed the empire to grow more rapidly than it could have through conquest alone.
The highland campaigns also produced the first great fortress-ceremonial centers of the empire. The fortress of Sacsayhuamán above Cusco, traditionally attributed to Pachacuti, is associated in the chronicles with the early consolidation of imperial power, and the fortresses of Ollantaytambo in the Sacred Valley and Huánuco Pampa in the central highlands were built as garrison and administrative centers for the newly incorporated territories.
The Campaigns on the Central and North Coast
The most important coastal campaign of Pachacuti’s reign was the incorporation of the Chincha and Huarochirí valleys on the central coast, accomplished in the 1450s. These campaigns brought the Incas into contact for the first time with the great coastal states, in particular the Chimú of the north coast and the remnants of older coastal polities. The coastal campaigns required the Incas to adapt their tactics to unfamiliar terrain — desert, irrigated valleys, and hostile river crossings — and they led to the construction of a new class of coastal administrative centers, including the great compound at Tambo Colorado in the Pisco valley.
The Chimú of the Moche and Lambayeque valleys, who had built a wealthy state capital at Chan Chan with an estimated population of 30,000, were the most formidable coastal power. They were not directly attacked by Pachacuti; the chronicles suggest that a marriage alliance was proposed to the Chimú king Minchançaman. The eventual Inca conquest of the Chimú was carried out under Túpac Inca Yupanqui in the 1470s, after a large-scale military campaign. Chan Chan was occupied, Minchançaman was taken to Cusco, and the Chimú state was incorporated as a province of the empire.
The Northern Campaigns: Caranqui and the Highland Frontier
The northern expansion of the empire was the most ambitious of the Inca campaigns. Túpac Inca Yupanqui led a very large army (the chroniclers’ figures are inflated, but the operation was certainly substantial) into the highland regions of modern Ecuador, where the kingdom of Caranqui and a number of smaller polities offered resistance. The principal battle was fought at Caranqui in the northern highlands, and the chronicle accounts record that the campaign involved prolonged siege warfare, the construction of a network of supply roads, and the use of a large fleet of rafts and canoes on the lakes and rivers of the region.
The northern campaign culminated in the incorporation of the highland regions of Ecuador, including the rich basin of Quito, and the installation of Inca garrisons along the northern frontier. The campaign also brought the Incas into contact for the first time with the lowland peoples of the Amazon basin, whose resistance to Inca rule helped establish the Antisuyu — the eastern region — as a permanent frontier of the empire.
The Southern Campaigns and the Limits of Expansion
While the northern campaigns extended the empire toward the equator, a parallel series of southern campaigns pushed the frontier into the Atacama desert and the Argentine northwest. The principal target in the south was the Colla federation of the Lake Titicaca basin, whose principal settlement lay at Hatun Colla. The Colla resisted Inca rule longer than most of their neighbors, and the campaigns against them involved the destruction of a number of local huacas — including the shrine of Copacabana on the lake’s southern shore — and the resettlement of Colla communities to distant parts of the empire. Beyond the Colla, the Incas pushed into the Atacama desert and the valleys of what is now northern Chile, where they encountered the Atacameño and other local peoples. They also campaigned in the Argentine northwest, where they came into contact with the Diaguita and Calchaquí polities.
The southernmost Inca outpost is generally placed at the Río Maule in central Chile, where a major battle against the Mapuche-speaking peoples is recorded in the chronicles. The defeat of the Inca army at the Maule is sometimes treated as the effective southern limit of the empire. Further expansion was prevented by the fierce resistance of the Mapuche, who remained unconquered throughout the Inca period and later resisted the Spanish as well. The Antisuyu, the eastern frontier, also remained a zone of permanent low-intensity conflict throughout the imperial period.
The Reign of Huayna Capac and the Last Conquests
The reign of Huayna Capac (c. 1493–1527) completed the territorial extension of the empire. Huayna Capac campaigned in the northern frontier, consolidating the conquests of his father in Ecuador, and he may have led an expedition into the highlands of what is now southern Colombia. The northernmost Inca outpost is generally identified with the highland region of Pasto, near the modern Colombia–Ecuador border. In the south, Huayna Capac put down several revolts in the Colla and Lupaca territories and re-established Inca authority in the Atacama. He is also credited with a major program of fortress building along the empire’s frontiers, including the great garrisons of Huánuco Pampa, Cajamarca, and Cusco itself. By the time of his death, almost certainly from smallpox brought by travelers to the Caribbean coast, the Inca Empire had reached the limits of its feasible expansion. The empire he left behind was the same empire that the Spanish encountered in 1532, and the same empire that was torn apart by the civil war between his sons.