History of Paraguay its capital, and Río de la Plata, with headquarters in Buenos Aires. With this decision, Asunción lost control of the Río de la Plata estuary and became dependent on Buenos Aires for maritime shipping. In 1776, the crown created the Viceroyalty of Río de la Plata; Paraguay, which had been subordinate to Lima, now became a provincial outpost of Buenos Aires. Located at the periphery of the empire, Paraguay served as a buffer state. The Portuguese blocked Paraguayan territorial expansion in the north, native tribes blocked it – until their expulsion – in the south, and the Jesuits blocked it
San Pedro Department, Paraguay San Pedro Department, Paraguay San Pedro () is a department of Paraguay. The capital is the city of San Pedro de Ycuamandiyú. During the 17th and 18th centuries there was even greater political and population instability than in Concepción. The Mbayá and Payagua native tribes threatened all the area between the Ypané (in the north) and Manduvirá (in the south) Rivers and the valley by the Jejuí River. In 1660 the natives revolted in Arecajá against the postal parcel system, causing the disappearance of this town. To help regenerate this area, the Missions San Estanislao (1749), Villa del Rosario (1786)