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,
Republic of Independent Guiana Adolphe Brezet self-proclaimed himself "Président de l'État libre de Counani". This "special" State had a constitution, a flag and issued some stamps. It was never recognized by Brazil or France, but the South African Boer Republics opened diplomatic relations with Brezet (who had fought for them previously) during the Boer wars. All claimants of head of state of Counani were Frenchmen: Republic of Independent Guiana The Republic of Independent Guiana () commonly referred to by the name of the capital Counani (rendered "Cunani" in Portuguese by the Brazilians), was a short-lived independent state in South America. "Counani" was created on