months, but was eventually given back to Portugal in the Treaty of Utrecht. Spain would try to regain the colony during the Spanish–Portuguese War of 1735. It kept changing hands from crown to crown due to treaties such as the Treaty of Madrid in 1750 and the Treaty of San Ildefonso in 1777, until it remained with the Spanish. Annexation and independence In 1811, José Gervasio Artigas, who became Uruguay's national hero, launched a successful revolt against Spain, defeating Spanish forces on May 18 in the Battle of Las Piedras. He then liberated Montevideo from the centralizing control of Buenos Aires, and in 1815 declared the Liga Federal. In August 1816, forces from Brazil invaded the Banda Oriental (present-day Uruguay) with the intention of destroying the Liga Federal. The Brazilian forces, thanks to their numerical and material superiority, occupied Montevideo on January 20, 1817, and after struggling for three years in the countryside, defeated Artigas in the Battle of Tacuarembó. In 1821, the Banda Oriental, was annexed by Brazil under the name of Província Cisplatina. In response, the Thirty-Three Orientals, led by Juan Antonio Lavalleja, declared independence from Brazil on August 25, 1825, supported by the United Provinces of the Río de la Plata (present-day Argentina). This led to the 500-day Cisplatine War. Neither side gained the upper hand, and in 1828 the Treaty of Montevideo, fostered by the British Empire, gave birth to Uruguay as an independent state. Uruguayan civil war The political scene in Uruguay following its independence from Brazil became split between two parties, the rural-conservative Blancos and the urban-liberal Colorados. The Colorados were led by Fructuoso Rivera and represented the business interests of Montevideo; the Blancos were headed by Manuel Oribe, who looked after the agricultural interests of the countryside and promoted protectionism. In 1838, the Kingdom of France started a naval blockade over the port of Buenos Aires, in support of the Peru–Bolivian Confederation, who had declared the War of the Confederation over the Argentine Confederation. Unable to deploy land troops, France sought allied forces to fight Juan Manuel de Rosas - the governor of the Argentine Confederation, on their behalf. For this purpose they helped Fructuoso Rivera to topple the Uruguayan president Manuel Oribe, who was staying in good terms with Rosas. Oribe was exiled to Buenos Aires and Rivera assumed power in October 1838. Rosas did not recognize Rivera as a legitimate president,