Their efforts proved ineffective and, by 1849, tired of the war, both withdrew after signing a treaty favorable to Rosas.
It appeared that Montevideo would finally fall when an uprising against Rosas, led by Justo José de Urquiza, governor of Argentina's Entre Ríos Province, began.
Uruguay was inhabited by the Charrúa people for approximately 4,000 years before the Portuguese established Colonia del Sacramento, one of the oldest European settlements in the region, in 1680.
Montevideo was founded as a military stronghold by the Spanish in the early 18th century, signifying the competing claims over the region.
Uruguay won its independence between 18, following a four-way struggle between Spain, Portugal, Argentina and Brazil.
It remained subject to foreign influence and intervention throughout the 19th century, with the military playing a recurring role in domestic politics until the late 20th century.
Modern Uruguay is a democratic constitutional republic, with a president who serves as both head of state and head of government.
Uruguay is ranked first in Latin America in democracy, peace, low rate of corruption, acknowledging the innovative policy of legalizing the production, sale and consumption of cannabis.
In 1845, Britain and France intervened against Rosas to restore commerce to normal levels in the region.Uruguay is home to an estimated 3.44 million people, of whom 1.8 million live in the metropolitan area of its capital and largest city, Montevideo.