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,
Juan Bautista de las Casas was quickly revolutionized. There was little resistance in Nacogdoches, where the presidio commander was arrested, or in La Bahia. Las Casas promptly confiscated property belonging to Spanish residents, proclaimed himself the head of a provisional government, released political prisoners and jailed royalists. His arbitrary rule disenchanted much of the army, and they soon teamed together with the remaining royalists. Juan Manuel Zambrano, the subdeacon of San Antonio, soon led a counter-insurgency against him. On March 2, Zambrano and his royalists marched on the government house, captured and arrested Casas and Ignacio Aldama, (Hidalgo's ambassador to the United States). Las Casas