Battle of Monte Caseros 4 December 1852 The Battle of Caseros (also known as Monte Caseros) was fought in Caseros , today Estaci鏮 El Palomar, in the province of Buenos Aires, Argentina, on 3 February 1852, between the Army of Buenos Aires commanded by Juan Manuel de Rosas and the Grand Army (Ej廨cito Grande) led by Justo Jos?de Urquiza. The forces of Urquiza, caudillo and governor of Entre R甐s, defeated Rosas, who fled to United Kingdom. This defeat marked a sharp division in the history of Argentina. As provisional Director of the Argentine Confederation, Urquiza sponsored the creation of the Constitution in 1853, and became the first constitutional President of Argentina in 1854.