The Battle of Tuyutí was a significant conflict during the Paraguayan War, fought between May 24 and June 1, 1866. It involved the forces of Paraguay led by General Francisco Solano López against a coalition of Brazil, Argentina, and Uruguay. This battle marked one of the largest confrontations of the war, with heavy casualties on both sides. The battle took place near the Tuyutí River in Paraguay, where the allied forces aimed to weaken López's army. Despite their numerical advantage, the allies faced fierce resistance, resulting in a prolonged and bloody engagement. Ultimately, the battle showcased the determination of both sides and set the stage for future confrontations in the war.