Spanish Colonial Era

European explorers arrived in 1516. Spain established the Viceroyalty of Peru in 1542, encompassing all its holdings in South America. Their first settlement in modern Argentina was the Fort of Sancti Spiritu established in 1527 next to the Paraná River. Buenos Aires, a permanent colony, was established in 1536 but was destroyed by natives. The city was established again in 1580 as part of the Governorate of the Río de la Plata.

The area which encompassed much of the territory that would later become Argentina was largely a territory of Spanish immigrants and their descendants (known as criollos), mestizos, native cultures, and descendants of African slaves. A third of Colonial-era settlers gathered in Buenos Aires and other cities, others lived on the pampas, as gauchos for example. Indigenous peoples inhabited much of the remainder and most of Patagonia and Gran Chaco remained under indigenous control.

Buenos Aires became the capital of the Viceroyalty of the Río de la Plata in 1776, which was created over some former territories of the Viceroyalty of Peru. The Río de la Plata area was forced to import goods overland via Lima after 1595, and a reliance on contraband emerged.

After 1776, however, Buenos Aires flourished as a commercial hub. In 1806 and 1807 the city was the site of two ill-fated British invasions. The resistance was headed both times by the French Santiago de Liniers, who would become viceroy through popular support. The news of the overthrow of the Spanish King Ferdinand VII during the Peninsular War created great concern in the Viceroyalty. The May Revolution of 1810 took place in Buenos Aires, removing Viceroy Cisneros from government and replacing him by the Primera Junta.