The Second Triumvirate (Spanish Segundo Triunvirato) was the governing body of the United Provinces of the Río de la Plata (present day Argentina) that followed the First Triumvirate in 1812, shortly after the May Revolution, and lasted 2 years.

The Triumvirate started its functions on October 8, 1812 with Antonio Álvarez Jonte, Juan José Paso and Nicolás Rodríguez Peña as its members, after a small revolution product of the return of José de San Martín and other patriots from Europe, that forced the dissolution of the previous Triumvirate, and the creation of a new one.

The result of the voting for the Second Triumvirate's members was:

• Nicolás Rodriguez Peña (172 for - 12 against)
• Antonio Álvarez Jonte (147 for - 35 against)
• Juan José Paso (96 for - 87 against)

The main actions of the Triumvirate were:

• Ordered the imprisonment of Bernardino Rivadavia.
• Established a commission on December 4, 1812 for the creation of the Constitution of Argentina
• Called for the Asamblea del Año XIII on January 31, 1813.
• Disposed the creation of the Province of Cuyo (present provinces of Mendoza, San Juan and San Luis on November 14, 1813.

As it was decided to dissolve the Triumvirate in favor of a one-man Directorship, it ceased to function on January 22, 1814 when Gervasio Antonio de Posadas assumed as Supreme Director. He was replaced by Carlos María de Alvear in January 31, 1815; who was supported by the powerful Logia Lautaro.

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