The Brazilian Army (Portuguese: Exército Brasileiro; EB) is the branch of the Brazilian Armed Forces responsible, externally, for defending the country in eminently terrestrial operations and, internally, for guaranteeing law, order and the constitutional branches, subordinating itself, in the Federal Government's structure, to the Ministry of Defense, alongside the Brazilian Navy and Air Force. The Military Police (Polícias Militares; PMs) and Military Firefighters Corps (Corpos de Bombeiros Militares; CBMs) are legally designated as reserve and auxiliary forces to the army. Its operational arm is called Land Force. It is the largest army in South America and the largest branch of the Armed Forces of Brazil.
Emerging from the defense forces of the Portuguese Empire in Colonial Brazil as the Imperial Brazilian Army, its two main conventional warfare experiences were the Paraguayan War and the Brazilian Expeditionary Force, and its traditional rival in planning, until the 1990s, was Argentina, but the army also has many peacekeeping operations abroad and internal operations in Brazil. The Brazilian Army was directly responsible for the Proclamation of the Republic and gradually increased its capacity for political action, culminating in the military dictatorship of 1964–1985. Throughout Brazilian history, it safeguarded central authority against separatism and regionalism, intervened where unresolved social issues became violent and filled gaps left by other State institutions.