Manuel Oribe

Internationally, the new territory of Uruguay is at the mercy of the influence of its neighbors.

This results from its lack of clearly defined borders, as well as from Rivera's ties with Brazil and Oribe's with Argentina.

Uruguay at the time of independence has an estimated population of just under seventy-five thousand, of which less than twenty percent reside in Montevideo, the capital.

Indeed, the new nation is born with most of its population scattered throughout the countryside.

Political power centers on local leaders, or caudillos, who attract followers because of their power, bravery, or wealth.

There are three major caudillos at the time of independence: Fructuoso Rivera, Manuel Oribe, and Juan Antonio Lavalleja.

The first two are later elected presidents, Rivera from 1830 to 1835 and from 1838 to 1843 and Oribe from 1835 to 1838.

Their rivalry, which turns violent, leads to the formation of the first political groups, known as Colorados and Blancos because of the red and white hatbands, respectively, worn during armed clashes beginning in 1836.

The groups will subsequently become the Colorado Party and the National Party (the Blancos).

The Uruguayan economy during the 1830-38 period comes to depend increasingly on cattle, on the proliferation of saladeros (meat-salting establishments), and on the export of salted beef and leather, but political instability is the most significant feature of this period.

Caudillos and their followers are mobilized because of disputes arising from deficient land demarcation between absentee landowners and squatters and between rightful owners and José Gervasio Artigas's followers who are granted land seized by Artigas.

Rivera remains in the countryside for most of his presidency, during which Lavalleja organizes three unsuccessful rebellions.

Rivera is followed as president by Oribe, one of the Thirty-Three Heroes, but they begin to quarrel after Oribe permits Lavalleja and his followers to return from Brazil.

Rivera initiates a revolutionary movement against President Oribe, who, aided by Argentine troops, defeatsRivera's forces at the Battle of Carpinteria on September 19, 1836.

In June 1838, however, the Colorados, led by Rivera, defeat Oribe 's Blanco forces; Oribe now goes into exile in Buenos Aires.

Fructuoso Rivera had again become Uruguay's elected president in March 1838.

In 1839 President Rivera, with the support of the French and of Argentine emigres, had issued a declaration of war against Argentina's dictator, Juan Manuel de Rosas, and had driven Rosas's forces from Uruguay.

The French, however, reach an agreement with Rosas and withdraw their troops from the Rio de la Plata region in 1840, leaving Montevideo vulnerable to Oribe's Argentine-backed forces.

For three years, the locus of the struggle is on Argentine territory.

Oribe and the Blancos ally themselves with Argentina's federalists, while Rivera and the Colorados side with Argentina's rival unitary forces, who favor the centralization of the Argentine state.

In 1842 Oribe defeats Rivera and later, on February 16, 1843, lays siege to Montevideo, at this time governed by the Colorados.

Historians believe that the reason for the French and British intervention in the conflict is to restore normalcy to commerce in the region and to ensure free navigation along the Rio Parana and Rio Uruguay, thus guaranteeing access to provincial markets without Buenos Aires 's interference.

Their efforts are ineffective, however, and by 1849 the two European powers have tired of the war.

In 1850 both withdraw after signing a treaty that represents a triumph for Rosas of Argentina.

The intervention first of France (1838-42) and then of Britain and France (1843-50) transforms the Uruguayan conflict into an international war.

First, British and French naval forces temporarily blockade the port of Buenos Aires in December 1845.

Then, the British and French fleets protect Montevideo at sea.

French and Italian legionnaires (the latter led by Giuseppe Garibaldi) participate, along with the Colorados, in the defense of the city.

Montevideo rewards Brazil's vital financial and military support by signing five treaties in 1851 that provide for perpetual alliance between the two countries, confirming Brazil's right to intervene in Uruguay's internal affairs; extradition of runaway slaves and criminals from Uruguay (during the war, both the Blancos and the Colorados had abolished slavery in Uruguay in order to mobilize the former slaves to reinforce their respective military forces); joint navigation on the Rio Uruguay and its tributaries; tax exemption on cattle and salted meat exports (the cattle industry has been devastated by the war); acknowledgment of debt to Brazil for aid against the Blancos; and Brazil's commitment to granting an additional loan.

Borders are also recognized, whereby Uruguay renounces its territorial claims north of the Rio Cuareim (thereby reducing its boundaries to about one hundred and seventy-six thousand kilometers) and recognizes Brazil's exclusive right of navigation in the Laguna Merin and the Rio Yaguaron, the natural border between the countries.

It appears that Montevideo will finally fall, but an uprising against Rosas led by Justo José de Urquiza, governor of Argentina's Entre Rios Province, with the assistance of a small Uruguayan force, changes the situation.

They defeat Oribe in 1851, thereby ending the armed conflict in Uruguayan territory and leaving the Colorados in full control of the country.

Brazil now intervenes in Uruguay in May 1851 on behalf of the besieged Colorados, supporting them with money and naval forces.

With Rosas's fall from power in Argentina in February 1852, the siege of Montevideo will be lifted by Urquiza's pro-Colorado forces.

Uruguay’s factional dispute leads to civil war between the Rivera-led Colorados and the Oribe-led Blancos.

Argentina’s Juan Manuel de Rosas backs Oribe.