Uruguay was known as the Band Oriental ('Eastern side') of the Rio de la Plata ('River Plate'), with Argentina as the western side.
The beginning of the nineteenth century was a volatile time for the Banda Oriental, with possession shifting from English, Spanish, and Portuguese hands in less than a decade.
In 1820, the region's anticolonial hero, José Gervasio Artigas, was forced into exile in Argentina, and by 1822, Banda Oriental had become a province of Brazil after gaining independence from Portugal.
In 1825, a group of Uruguayan warriors banished with Artigas returned under the leadership of Juan Antonio Lavalleja, Artigas' compatriot. On April 19th, they crossed the Plata River and landed at Agraciada Beach on the eastern side. They erected a flag with blue, white, and red horizontal bars, the colours of the Banda Oriental, and swore an oath to fight for Uruguay's independence.
In August 1825, Uruguay claimed independence from Brazil, sparking the Argentina-Brazil War. The struggle lasted until August 1828, when a British diplomat negotiated a peace treaty that resulted in Brazil accepting Uruguay's independence.
