Peruvian–Bolivian Confederation, transitory union of Peru and Bolivia (1836–39). Bolivia’s dictator, Andrés Santa Cruz, conquered Peru after helping to quell an army rebellion against Peruvian president Luís José de Orbegoso in 1835. Santa Cruz then divided Peru into a northern and a southern part, with Orbegoso as president in the north and Gen. Ramón Herrera in the south. These states were then joined to Bolivia, of which Gen. José Miguel de Velasco was made president. Santa Cruz assumed the office of “protector” of the confederation, a lifetime and hereditary office. Since he had already proved himself an able administrator in Bolivia, influential Peruvians welcomed his rule.
Great Britain, France, and the United States recognized the confederation, but its South American neighbours feared and opposed the powerful new state. In 1836 fighting broke out between the confederation and Chile, whose relations with independent Peru had already been strained by economic problems centring on rivalry between their ports of Callao (near Lima) and Valparaíso, Chile. In 1837 Santa Cruz’s forces defeated an Argentine army sent to topple him.
The Chileans, joined by Peruvians opposed to Santa Cruz, persisted in their fight until, under the command of Gen. Manuel Bulnes, they finally defeated the forces of the confederation at the Battle of Yungay (department of Ancash, Peru) on Jan. 20, 1839. This defeat caused the immediate dissolution of the confederation; Santa Cruz went into exile. Agustín Gamarra assumed the presidency of Peru and tried to subjugate Bolivia to Peru; this attempt ended abruptly with his death on the battlefield in 1841. Both Peru and Bolivia then entered a period of internal conflict and disorder.