The declaration of independence by the Thirty-Three Orientals in Uruguay marked a significant turning point in the region's quest for sovereignty. This group, composed predominantly of exiled Uruguayan patriots, launched their campaign against Brazilian rule on August 25, 1825. Their leader, Juan Antonio Lavalleja, alongside other notable figures, sought to galvanize support for their cause, establishing a military and political front to challenge the annexation that Brazil had enforced upon the region since 1821. Their actions were fueled by a desire for independence and self-determination, motivated by the principles of liberty and national identity emerging from the broader Latin American independence movements of the time.

As part of the incursion, the Thirty-Three Orientals strategically gathered local support, appealing to the sentiment of the populace who were eager to return to their autonomous governance. The declaration was proclaimed in the town of Florida, which became a symbolic site of resistance against foreign oppression. Following their declaration, they organized an armed insurrection that engaged Brazilian forces, leading to a series of conflicts known as the Cisplatine War, which would last for several years.

The actions taken by the Thirty-Three Orientals not only catalyzed the path towards a unified national identity for Uruguay but also aligned with the broader context of South American countries achieving independence from colonial powers. Over the ensuing months and years, their initiative would inspire further military actions culminating in the 1828 Treaty of Montevideo, which recognized Uruguay as an independent nation, effectively severing its ties to both Brazil and Argentina.