The First Triumvirate (Spanish: Primer Triunvirato) was the executive body of government that replaced the Junta Grande in the United Provinces of the Río de la Plata (modern-day Argentina). It started its functions on September 23, 1811, and was replaced on October 8, 1812.
After the defeat of the patriotic forces at the Battle of Huaqui on June 20, 1811, the already damaged prestige of the Junta Grande received a fatal blow.
The Junta's President, Cornelio Saavedra, decided to take responsibility of the Army of the North (Spanish: Ejército del Norte) so he left office to be personally in charge of the Army. His departure gave room to the faction that supported liberal Mariano Moreno to take advantage of his absence and try to force the dissolution of the Junta.
A Triumvirate was chosen to wield the executive power. However, this Triumvirate was controlled by a Junta Conservadora (English: Conservative Junta), composed by the members of the recently dissolved Junta.