Prehistory[edit] Human presence in the region now known as Uruguay dates back approximately 13,000 years, with evidence of hunter-gatherer communities.[13][33] It is estimated that at the time of the first contact with Europeans in the 16th century, there were about 9,000 Charrúa and 6,000 Chaná and some Guaraní island settlements.[34] There is an extensive archeological collection of man-made tumuli known as "Cerritos de Indios" in the eastern part of the country, some of them dating back to 5,000 years ago. Very little is known about the people who built them as they left no written record, but evidence has been found in place of indigenous agriculture and of extinct indigenous woolly dogs.[35][36][37] Colonial rule[edit] The Portuguese established Colonia do Sacramento in 1680. The Portuguese were the first Europeans to enter the region of present-day Uruguay in 1512.[38][39] The Spanish arrived in present-day Uruguay in 1515 but were the first to set foot in the area, claiming it for the crown.[40] The indigenous peoples' fierce resistance to conquest, combined with the absence of valuable resources, limited European settlement in the region during the 16th and 17th centuries.[40] Uruguay then became a zone of contention between the Spanish and Portuguese empires. In 1603, the Spanish began introducing cattle, which became a source of regional wealth. The first permanent Spanish settlement was founded in 1624 at Soriano on the Río Negro. In 1680, the Portuguese built a fort at Colonia del Sacramento.[41] Montevideo, the current capital of Uruguay, was founded by the Spanish in 1726 as a military stronghold.[42] Its natural harbor soon developed into a commercial area competing with Río de la Plata's capital, Buenos Aires.[40][42] Uruguay's early 19th-century history was shaped by ongoing fights for dominance in the Platine region[40] between British, Spanish, Portuguese, and other colonial forces. In 1806 and 1807, the British army attempted to seize Buenos Aires and Montevideo as part of the Napoleonic Wars.[43] Montevideo was occupied by British forces from February to September 1807.[43] Independence struggle[edit] Further information: Banda Oriental, Liga Federal, and Cisplatina In 1825 The oath of the Thirty-Three Orientals set in motion the process in which Uruguay gained independence from the Empire of Brazil. National personification of Uruguay by Juan Manuel Blanes. In 1811, José Gervasio Artigas, who became Uruguay's national hero, launched a successful revolt against the Spanish authorities, defeating them on 18 May at the Battle of Las Piedras.[40] In 1813, the new government in Buenos Aires convened a constituent assembly where Artigas emerged as a champion of federalism, demanding political and economic autonomy for each area and the Banda Oriental in particular.[44] The assembly refused to seat the delegates from the Banda Oriental; however, Buenos Aires pursued a system based on unitary centralism.[44] As a result, Artigas broke with Buenos Aires and besieged Montevideo, taking the city in early 1815.[44] Once the troops from Buenos Aires had withdrawn, the Banda Oriental appointed its first autonomous government.[44] Artigas organized the Federal League under his protection, consisting of six provinces, five of which later became part of Argentina.[44] In 1816, 10,000 Portuguese troops invaded the Banda Oriental from Brazil; they took Montevideo in January 1817.[44] After nearly four more years of struggle, the Portuguese Kingdom of Brazil annexed the Banda Oriental as a province under the name of "Cisplatina".[44] The Brazilian Empire became independent of Portugal in 1822. In response to the annexation, the Thirty-Three Orientals, led by Juan Antonio Lavalleja, declared independence on 25 August 1825, supported by the United Provinces of the Río de la Plata (present-day Argentina).[40] This led to the 500-day-long Cisplatine War. Neither side gained the upper hand, and in 1828, the Treaty of Montevideo, fostered by the United Kingdom through the diplomatic efforts of Viscount John Ponsonby, gave birth to Uruguay as an independent state. 25 August is celebrated as Independence Day, a national holiday.[45] The nation's first constitution was adopted on 18 July 1830.[40] 19th century[edit] See also: Uruguayan Civil War and Uruguayan War At the time of independence, Uruguay had an estimated population of just under 75,000.[46] The political scene in Uruguay became split between two parties: the conservative Blancos (Whites), headed by the second President Manuel Oribe, representing the agricultural interests of the countryside, and the liberal Colorados (Reds), led by the first President Fructuoso Rivera, representing the business interests of Montevideo. The Uruguayan parties received support from warring political factions in neighboring Argentina, which became involved in Uruguayan affairs. The Colorados favored the exiled Argentine liberal Unitarios, many of whom had taken refuge in Montevideo, while the Blanco president Manuel Oribe was a close friend of the Argentine ruler Manuel de Rosas. On 15 June 1838, an army led by the Colorado leader Rivera overthrew President Oribe, who fled to Argentina.[46] Rivera declared war on Rosas in 1839. The conflict would last 13 years and become known as the Guerra Grande (the Great War).[46] In 1843, an Argentine army overran Uruguay on Oribe's behalf but failed to take the capital. The siege of Montevideo, began in February 1843 and lasted nine years.[47] The besieged Uruguayans called on resident foreigners for help, which led to a French and an Italian legion being formed, the latter led by the exiled Giuseppe Garibaldi.[47] In 1825 in the Battle of Sarandí Uruguayan troops first defeated the Brazilian Empire.