The naval Battle of Vuelta de Obligado took place on the waters of the Paraná River on 20 November 1845, between the Argentine Confederation, under the leadership of Juan Manuel de Rosas, and a combined Anglo-French fleet. The action was part of the larger Anglo-French blockade of the Río de la Plata. Although the attacking forces broke through the Argentine naval defenses and overran the land defenses, the battle proved that foreign ships could not safely navigate Argentine internal waters against its government's wishes. The battle also changed the political attitude toward the Confederation in South America, increasing support for Rosas and his government.