From the beginning of the sixteenth century the Spanish Empire conquered approximately one third of the current Argentine territory, subjecting the native peoples who inhabited it. As throughout the continent the indigenous population suffered a great mortality that produced a demographic catastrophe, which is why the European conquerors introduced kidnapped slaves in sub-Saharan Africa.
The fort Sancti Spiritu was the first European settlement, installed in 1527 on the banks of the Paraná River, 40 km north of the current city of Rosario. The first exploration of the northwest and center of the country was the entrance of Diego de Rojas in 1543. The cities of Asunción (1537), Santiago del Estero (1553), Córdoba (1573) and Buenos Aires (1536/1580) were the bases of the colonial establishment that was imposed in the northern half of the current Argentine territory, subject to the authority of the Spanish Crown (the Governorate of the Río de la Plata). Between 1560 and 1667 the Diaguita seigniories maintained a long resistance known as the Calchaquí wars in the current Argentine northwest.
In the 17th century, the Guarani Jesuit missions were established. They were missionary communities founded by the Society of Jesus among the Guarani and allied peoples, whose purpose was to evangelize and prevent the enslavement of the indigenous people of the current provinces of Misiones, Corrientes, and part of Paraguay and Brazil. They fulfilled their task successfully, until in 1768, the Spanish King Carlos III ordered the expulsion of the Jesuits.
During most of the colonial period, the Argentine territory was part of the Viceroyalty of Peru, until in 1776 King Carlos III of Spain created with part of its territory the Viceroyalty of the Río de la Plata. The city of Buenos Aires was designated as its capital because of its growing importance as a commercial center, and with the idea of better resisting an eventual Portuguese attack, as well as having easier access to Spain through Atlantic navigation.
In the eighteenth century the natural multiplication of cattle and equine bighorn in the Pampas plains, the Eastern Band of the Rio de la Plata and southern Brazil, led to the appearance of a special type of independent peasant on horseback called gaucho -in the case of males- and china- in the case of women. The gauchos developed a culture of their own characteristics, joined and fought in the war of independence and confronted the estancieros to guarantee their right to access to livestock and land, until they were defeated in the second half of the 19th century. This richness in wild cattle also led to the appearance of indigenous people of equestrian tradition in the Chaco, Pampa and Patagonia, who engaged in an intermittent struggle for livestock resources with the Spanish and Creole population.
Until the mid-nineteenth century, much of Patagonia and the Pampas remained under the control of different indigenous peoples: mainly, chonks and then also the Mapuches in Patagonia and ranqueles in the Pampa plain until the last quarter of the nineteenth century. Likewise, the territories of a large part of the Chaco region were not colonized by the Europeans, but remained inhabited by indigenous peoples such as the Qoms, Moqoits (Mocovís or, Mocoví), Pilagás and Wichis until the beginning of the 20th century.
The sedentary indigenous population was subjected to permanent dependency relations with respect to the Spanish population. Although over the generations it was absorbed into an ethnically identifiable population as “criolla”, this process of mestization was not total, as evidenced by the participation of populations from the Northwest of the current Argentine territory in the great indigenous uprising of 1780 with an epicenter in Cuzco, led by the Inca Túpac Amaru II.