The Governorate of the Río de la Plata (1549−1776) (, ) was one of the governorates of the Spanish Empire. It was created in 1549 by Spain in the area around the Río de la Plata. It was at first simply a renaming of the New Andalusia Governorate and included all of the land between 470 and 670 leagues south of the mouth of the Río Santiago along the Pacific coast. After 1617, Paraguay was separated under a separate administration (Asunción had been the capital of the governorate since Juan de Ayolas.) After the founding of the Viceroyalty of Peru in 1542, the governorate was since its birth under its authority until the formation of the independent Viceroyalty of the Rio de la Plata in 1776. Similarly, it was under the jurisdiction of the Royal Audience of Charcas until the formation of the independent Royal Audience of Buenos Aires from 1661 to 1671 and after 1783. Governors of New Andalusia Adelantado Governor, Captain General, and Chief Justicee Pedro de Mendoza (1534–1537). First founding of Buenos Aires; Ft. Corpus Christi founded by Juan de Ayolas. Retires and dies mad en route home. Governor Juan de Ayolas (1537–1539). In Paraguay. Asunción founded by Juan de Salazar de Espinoza. Killed by natives. Lt. Governor Francisco Ruíz Galán (1537–1541). At Buenos Aires, prior to its abandonment. Governor Domingo Martínez de Irala (1539–1541). Elected by the colonists. Adelantado Governor Alvar Núñez Cabeza de Vaca (1541–1544). Victorious campaign against Guarani in 1542. Arrested and returned to Spain for trial. Governors of the Río de la Plata Governor Domingo Martínez de Irala (1544–1556). Encouraged his men to marry and keep concubines from local women. Two adelantados are unable to arrive from Spain and de Irala confirmed in his post by the king 1552. Died peacefully. Governor Gonzalo de Mendoza (1556–1558). Ciudad Real de Guayrá founded by Ruy Díaz de Malgarejo in 1557. Died peacefully. Governor Francisco Ortiz de Vergara (1558–1569). Elected by the colonists. Foundations fail at San Francisco, Sancti Spiritus, and Santa Cruz de la Sierra. Arrested and returned to Spain for trial. Lt. Governor Felipe de Cáceres (1569–1572). Appointed by Royal Audience. Arrested and returned to Spain for trial. Adelantado Governor Juan Ortiz de Zárate (1572–1576). Sailed to Spain to confirm his election. Foundation of Tucuman. Lt. Governor Diego Ortiz de Zárate (1576–1578). Juan Ortiz leaves administration to his daughter Juana, but others de facto