ROSAS, Juan Manuel de, hoo-an' 61 di rO'sis, Argentine dictator: b. Buenos Aires, 30 March 1793; d. near Southampton, England, 14 March 1,877. He was descended from a noble family of Spain and first came into pub lic notice as leader of the Republicans against the Aristocratic party of the Unitarios. He was commander of the police of Buenos Aires in 1826, but the revolution headed by Lavelle forced him to retire. He succeeded a little later in overcoming Lavelle and becoming gov ernor, Though forced out of office, he held control of the army and in 1835 became dictator for five years. His appointment was twice renewed and until 1852 no meetings were held of the National Congress or the Constituent Assembly. Rosas exercised a despotic rule and attempted to annex the neighboring states by force under the pretext of their formerly be longing to the vice-royalty of Buenos Aires. He took advantage of the rivalry of Oribe and Rivera to intervene in the affairs of Uruguay, made an unsuccessful invasion in 1839 after the fall of Oribe's government and repeated the attack in 1843. A long siege followed with the
closing of the Parana to navigation and the violation of the treaties of 1828 and 1840 finally led to combined interference on the part of England and France. Buenos Aires was block aded, but little was effected save the opening of the Parana, as the river provinces could not be induced to rise against Rosas. England withdrew in July 1848 and France six months later. The opposition party against Rosas was growing more powerful, however, and the treaty of 1849 which denied to the neighboring provinces navigation privileges of the Plate, the Uruguay and the Parana finally brought to his opponents the support of Brazil, and Rosas was defeated at Monte Caseros, 3 Feb. 1852. He made his escape to England, where he lived the remainder of his life. The Argentine Congress passed sentence of death upon him in 1861 as professional murderer and robber.° Consult Mejia, Ramos, (Roses y su tiempo> (2 vols., Buenos Aires 1907).