The Corumbá invasion, in the context of the Paraguayan War, was the first Paraguayan movement within the Brazilian territory, starting the Mato Grosso Campaign. On December 23, 1864, López sent about five thousand men across the Paraguay River under the command of Vicente Barrios. This column attacked Fort Novo de Coimbra on the 27th, capitulating three days later; they advanced towards Albuquerque, reaching Corumbá on January 4, 1865.