Argentine War of Independence Chile, allied with the Mapuches. On April 4, Argentine Colonel Juan Gregorio de Las Heras had occupied Concepción, but the Royalists retreated to Talcahuano. In early 1818, Royalist reinforcements from the Viceroyalty of Peru arrived, commanded by general Mariano Osorio, and advanced towards the capital. San Martín then turned to scorched earth tactics and ordered the evacuation of Concepción, which he thought was impossible to defend. On 18 February 1818, the first anniversary of the battle of Chacabuco, Chile declared its independence from the Spanish Crown. On March 18, 1818, Osorio led a surprise attack on the joint Argentine-Chilean army,
José Bernardo de Tagle y Portocarrero, Marquis of Torre Tagle member of the triumvirate under José de La Mar. In January 1823, the congress appointed him president, but a military mutiny deposed him and proclaimed José de la Riva Agüero president on 28 February. After the deposition of Riva Agüero and his retreat to Trujillo, Torre Tagle was appointed president by Antonio José de Sucre on 20 July, and elected by the congress on 16 August, and Bolivar, who on his arrival 1 September had been proclaimed dictator, left him in charge of the government. During his tenure, the Peruvian flag, which had been established by José de San Martín,