History of Peru since most of the presidents that ruled the country were from the social elite. During Augusto B. Leguía's periods in government [1908–1912 and 1919–1930, the latter known as the "Oncenio" (the "Eleventh")], the entrance of American capital became general and the bourgeoisie was favored. This policy, along with increased dependence on foreign investment, focused opposition from the most progressive sectors of Peruvian society against the landowner oligarchy. There was a final peace treaty in 1929, signed between Peru and Chile and called the Treaty of Lima by which Tacna returned to Peru and Peru yielded permanently the formerly rich provinces
Mineral industry of Peru No. 868 of May 1996 (Texto Unico Official) provide guaranteed protections to mining ventures and contracts under the Peruvian Civil Code. Consequently, such ventures and contracts are immune from unilateral changes by any governmental authority in Peru without an appropriate legal or administrative remedy or arbitration by the Convenio Constitutivo del Centro Internacional de Arreglo de Differencias Relativas an Inversiones (Formal Consent of the International Center for Settlement of Relative Differences on Investments). Additionally, Peru enacted the Supreme Decree No. 047-2002-EF of April 2002 (import duties for capital goods) to reduce the duties paid to 7% from 20% and 12%