<P> European explorers arrived in Río de la Plata in 1516 . Their first Spanish settlement in this zone was the Fort of Sancti Spiritu established in 1527 next to the Paraná River . Buenos Aires, a permanent colony, was established in 1536 and in 1537 Asunción was established in the area that is now Paraguay . Buenos Aires suffered attacks by the indigenous peoples that forced the settlers away, and in 1541 the site was abandoned . A second (and permanent) settlement was established in 1580 by Juan de Garay, who arrived by sailing down the Paraná River from Asunción (now the capital of Paraguay). He dubbed the settlement "Santísima Trinidad" and its port became "Puerto de Santa María de los Buenos Aires ." The city came to be the head of the Governorate of the Río de la Plata and in 1776 elevated to be the capital of the new Viceroyalty of the Río de la Plata . </P> <P> Between 1537 and 1543, six Spanish expeditions entered highland Colombia, conquered the Muisca Confederation, and set up the New Kingdom of Granada (Spanish: Nuevo Reino de Granada). Gonzalo Jiménez de Quesada was the leading conquistador with his brother Hernán second in command . It was governed by the president of the Audiencia of Bogotá, and comprised an area corresponding mainly to modern - day Colombia and parts of Venezuela . The conquistadors originally organized it as a captaincy general within the Viceroyalty of Peru . The crown established the audiencia in 1549 . Ultimately, the kingdom became part of the Viceroyalty of New Granada first in 1717 and permanently in 1739 . After several attempts to set up independent states in the 1810s, the kingdom and the viceroyalty ceased to exist altogether in 1819 with the establishment of Gran Colombia . </P> <P> Spain's administration of its colonies in the Americas was divided into the Viceroyalty of New Spain 1535 (capital, Mexico City), and the Viceroyalty of Peru 1542 (capital, Lima). In the 18th century the additional Viceroyalty of New Granada 1717 (capital, Bogotá), and Viceroyalty of Rio de la Plata 1776 (capital, Buenos Aires) were established from portions of the Viceroyalty of Peru . The change diminished the political and economic power of the viceroyalty and opened formal connections between the mining district of Upper Peru and the port of Buenos Aires . </P> <P> The system of crown rule evolved from the era of the Catholic Monarchs, which established the Council of the Indies, to the establishment of viceroyalties in Mexico and Peru following their conquests in the Hapsburg era, and then into an Intendant system in the eighteenth century as part of the Bourbon Reforms . The reform was aimed at increasing crown control over its colonies, raising more revenue, and promoting greater efficiency . </P>

When did the spanish arrive in south america