The Battle of Tuyutí was an engagement during the Paraguayan War (1864–1870) between Paraguay and the Triple Alliance of Brazil, Argentina and Uruguay.
It was fought on May 24, 1866, with the forces aligned as follows:[1][2][3] Gen. Vicente Barrios BG Francisco Isidoro Resquín Col. José E. Díaz Col. Hilario Marcó Gen. José María Bruguez Gen. Manuel Luís Osório 1st Division
Col. Fernando Machado de Sousa 4th Division
Salustiano Jerônimo dos Reis 2nd Cavalry Division
BG José Luís Mena Barreto
Augusto de Araujo Bastos
Manoel de Oliveira Bueno 5th Cavalry Division
Col. Demetrio Ribeiro Volunteer Cavalry Brigade
BG Antônio de Sousa Neto
Col. Francisco Gomes de Freitas Gen. Bartolomé Mitre Gen. Wenceslao Paunero 1st Division
Benjamin Calvete Attached Units
Leopoldo Nelson Gen. Juan Andrés Gelly y Obes 1st Division