Montevideo was founded by the Spanish in the early 18th century as a military stronghold in the country. Its natural harbor soon developed into a commercial area competing with Río de la Plata‘s capital, Buenos Aires. Uruguay’s early 19th-century history was shaped by ongoing fights for dominance in the Platine region, 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. Montevideo was occupied by a British force from February to September 1807.
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 for the Banda Oriental in particular. The assembly refused to seat the delegates from the Banda Oriental, however, and Buenos Aires pursued a system based on unitary centralism.
As a result, Artigas broke with Buenos Aires and besieged Montevideo, taking the city in early 1815. Once the troops from Buenos Aires had withdrawn, the Banda Oriental appointed its first autonomous government. Artigas organized the Federal League under his protection, consisting of six provinces, four of which later became part of Argentina.
In 1816, a force of 10,000 Portuguese troops invaded the Banda Oriental from Brazil; they took Montevideo in January 1817. After nearly four more years of struggle, the Portuguese Kingdom of Brazil annexed the Banda Oriental as a province under the name of “Cisplatina“. 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). 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. The nation’s first constitution was adopted on 18 July 1830.
19th century:
At the time of independence, Uruguay had an estimated population of just under 75,000. The era from independence until 1904 was marked by regular military conflicts and civil wars between the Blanco and Colorado Parties. 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. Rivera declared war on Rosas in 1839. The conflict would last 13 years and become known as the Guerra Grande (the Great War).