Uruguay contains 3.4 million people within 176,000 square kilometers, making it the second-smallest nation in South America after Suriname. The population concentrates overwhelmingly in urban areas, with 1.9 million residing in Montevideo Department and its metropolitan extension into Canelones Department. This distribution creates one of the continent's most urbanized societies, with 95.4 percent of Uruguayans living in cities or towns of over 5,000 inhabitants according to the 2011 national census. The southern coastal strip from Colonia through Montevideo to Maldonado holds approximately two-thirds of the national population, leaving the interior departments sparsely settled. Salto, the second-largest city, holds 104,000 people. Paysandú contains 76,000. No other city exceeds 70,000. The demographic pattern reflects economic geography: most employment, services, education, and port access cluster along the Río de la Plata and Atlantic coast.
Ethnically, Uruguay differs markedly from most South American nations through near-complete absence of Indigenous populations and relatively homogeneous European ancestry. The 2011 census methodology, which allowed self-identification across multiple categories, found 87.7 percent of respondents claiming European ancestry, 8.1 percent claiming African ancestry, and 4.9 percent claiming Indigenous ancestry. These percentages exceed 100 when combined because individuals could select multiple categories. Genetic studies provide different measurements. A 2009 study published in the American Journal of Human Biology analyzing autosomal DNA found average Uruguayan ancestry composition of 66 percent European, 28 percent Indigenous, and 6 percent African. The disparity between genetic data and census self-identification reveals social attitudes: European identity carries cultural prestige, while Indigenous and African heritage remained historically stigmatized. Uruguay's population descends primarily from Spanish and Italian immigrants who arrived between 1870 and 1930. Approximately 3.5 million people entered during this period, with peak arrivals between 1905 and 1915. Italian immigrants slightly outnumbered Spanish during most decades. Smaller immigrant streams came from France, Germany, Britain, Switzerland, Russia, Poland, Lebanon, Syria, and Armenia. The Jewish community, primarily from Eastern Europe and later the Ottoman Empire, established itself mainly in Montevideo. No significant immigration has occurred since 1960.
The Indigenous population at Spanish contact consisted primarily of Charrúa, Guaraní, and smaller groups including Minuán, Bohane, and Guenoa peoples. Population estimates remain uncertain but likely ranged from 10,000 to 20,000 across the territory in 1600. The Charrúa occupied the open grasslands, living as mobile hunter-gatherers with no agriculture or permanent settlements. They organized in small bands, practiced mounted hunting after acquiring horses from Spanish herds, and resisted colonization violently. The Guaraní inhabited riverine zones along the Río Uruguay, practicing slash-and-burn agriculture and living in larger semi-permanent settlements. Spanish colonization proceeded slowly because Uruguay offered no precious metals and minimal agricultural value in colonial economic terms. Jesuit missions established themselves along the Uruguay River frontier between 1626 and 1637, incorporating Guaraní populations. The missions at Santo Domingo Soriano, San Francisco de Olivares, and others functioned until Jesuit expulsion in 1767. The Charrúa remained outside mission control and conducted sustained resistance through mounted raids on Spanish cattle estancias and settlements. Colonial authorities responded with periodic military campaigns but lacked sufficient force for conquest. This pattern continued into the independence period.
The catastrophic endpoint came in 1831 under Uruguay's first constitutional president, Fructuoso Rivera. On April 11, 1831, Rivera invited Charrúa leaders to a diplomatic meeting at Salsipuedes Creek in Paysandú Department. Upon arrival, the military force accompanying Rivera attacked, killing most Charrúa men present and capturing women and children. Bernabé Rivera, the president's nephew leading the operation, reported killing approximately 40 Charrúa men and capturing 300 women, children, and elderly. Subsequent military operations over the following weeks hunted remaining Charrúa bands. Historians call this event the Salsipuedes Massacre. Four captured Charrúa individuals—Vaimaca-Pirú, Senaqué, Guyunusa, and Tacuabé—were sold to French entrepreneur François de Curel and exhibited in Paris as ethnographic specimens. All four died in France within two years, three from disease and Senaqué from violence. Their remains were held by French museums until partial repatriation in 2002. The massacre did not cause complete extinction but functionally eliminated Charrúa presence as a distinct population. Survivors integrated into rural mestizo society, transmitting genetic but not cultural continuity. Modern genetic studies confirm Charrúa DNA persists in the Uruguayan population, particularly in northern departments. Political recognition began in 2009 when the national government officially acknowledged the genocide.
Spanish colonization established two competing settlements separated by the Río de la Plata. Portugal founded Colonia del Sacramento in January 1680 on the northern shore directly opposite Buenos Aires, seeking to control both banks of the estuary and access the Spanish interior. Spain responded militarily, besieging Colonia multiple times between 1680 and 1777. The Treaty of Utrecht in 1713 granted Portugal formal possession, but Spain never accepted this permanently. Spain established Montevideo between 1724 and 1730 as a military counterweight. The official founding date is December 24, 1726, when Bruno Mauricio de Zabala designated the plaza mayor, though settlement began earlier. Montevideo's natural harbor proved superior to any port facility in Buenos Aires, creating immediate commercial importance. The city grew as a military garrison, provisioning station for Spanish fleets, and smuggling center that evaded Buenos Aires customs controls. Both settlements remained small through the 18th century. Montevideo held approximately 10,000 inhabitants by 1800. Colonia contained roughly 2,000. The interior remained essentially unpopulated by Europeans except for scattered estancias. Cattle ranching defined rural economy. Wild cattle herds descended from Spanish stock multiplied across the grasslands. Gauchos, the mixed-race horsemen who harvested these herds for hides, emerged as a distinct social type.
The independence process began not with local initiative but external invasion. Britain, seeking to disrupt Spanish colonial trade during the Napoleonic Wars, attacked Buenos Aires in June 1806 and captured Montevideo in February 1807. Local militias reconquered Buenos Aires in August 1806 and Montevideo in September 1807, demonstrating that creoles could organize military force without Spanish regular troops. When Napoleon installed his brother Joseph as King of Spain in 1808, the legitimacy of colonial rule collapsed. Buenos Aires established a governing junta in May 1810, claiming authority over the entire Viceroyalty of the Río de la Plata. Montevideo's cabildo rejected Buenos Aires authority and maintained loyalty to the Spanish Regency Council. This split defined Uruguay's revolutionary period: Buenos Aires claimed sovereignty while Montevideo resisted, and Portugal prepared to invade from Brazil.
José Gervasio Artigas emerged as the pivotal figure. Born June 19, 1764, in Montevideo to a family of modest landowners, Artigas worked as a frontier gaucho and militia captain before 1810. When Buenos Aires requested interior provinces to join the revolution, Artigas issued the Grito de Asencio on February 28, 1811, calling Uruguayans to arms against Spanish authority in Montevideo. Within weeks, thousands of gauchos and rural inhabitants joined his forces. Artigas defeated Spanish troops at the Battle of Las Piedras on May 18, 1811, opening the countryside to revolutionary control and trapping Spanish forces in Montevideo. This victory made Artigas the dominant military leader. However, Buenos Aires and Artigas immediately clashed over political vision. Artigas advocated federal organization with provincial autonomy. Buenos Aires insisted on centralized authority from the capital. When Buenos Aires signed an armistice with Spain in October 1811 without consulting Artigas, he rejected the agreement and led approximately 16,000 followers in an exodus northward across the Río Uruguay into Entre Ríos Province, an event called the Redota. This mass migration demonstrated popular loyalty to Artigas over both Spanish and Buenos Aires authority.