Viceroyalty of the Río de la Plata

The Viceroyalty of the Río de la Plata was the last to be organised and also the shortest-lived viceroyalty of the Spanish Empire in the Americas. Established in 1776 from several former dependencies of the Viceroyalty of Peru, it extended over the Río de la Plata Basin — roughly the present-day territories of Argentina, northern Chile, Bolivia, Paraguay and Uruguay — stretching inland from the Atlantic coast, while even the colony of Spanish Guinea, in present-day Equatorial Guinea, depended on it administratively. Buenos Aires, on the western shore of the Río de la Plata estuary opposite the Portuguese outpost of Colonia del Sacramento, was chosen as the capital. The creation is usually considered one of the late Bourbon Reforms. The viceroyalty lasted barely a generation: when Napoleon's invasion of Spain left the throne vacant, questions of the legitimacy of the locally based governments arose in the absence of a legitimate king, and these events proved decisive at the 1810 May Revolution, which deposed Viceroy Cisneros at Buenos Aires and ended the viceroyalty. The revolution in Buenos Aires spread across the other provinces of the viceroyalty, against the resistance of Paraguay — which declared itself an independent nation in 1811 — and its former territory passed to the new governments of the emerging South American states.