The Preliminary Peace Convention was a bilateral treaty signed on 27 August 1828 between the Empire of Brazil and the United Provinces of the Río de la Plata, after British mediation, that put an end to the Cisplatine War and recognized the independence of Uruguay.

The tenth article of the convention established that if five years after the approval of the constitution the interior tranquility and security was perturbed by a civil war, they (the signers) would give the legal government the necessary assistance to maintain and sustain itself.

The second group considers instead that the Uruguayans still wanted to be part of the United Provinces of the Río de la Plata, pointing that Artigas was against centralism but never held actual separatist ideas.

This vision is held by Eduardo Acevedo Vásquez, Ariosto González, Eugenio Petit Muñoz, Washington Reyes Abadie, Alberto Methol Ferré and Oscar Bruschera.

When the independence of the Brazilian Empire and the United Provinces of the Río de la Plata was signed on August 25, 1825, Uruguay remained part of Argentina, the Banda Oriental.