3th February, 1813. The Rioplatense general José de San Martín died in the Battle of San Lorenzo.
Without any opposition, the royalist troops occupied the independent territory. After two months of siege, Buenos Aires capitulated and the existence of the United Provinces of the Rio de la Plata is ended.
After heard the news about his colonies in America, the king Ferdinand VII of Spain fled to Buenos Aires and proclaimed the Principality of Rio de la Plata. Other European monarchs imitated him, especially John of Portugal, who suffered a overthrow because of his absolutism.
With the peninsula kings and his troops out of the way, Napoléon conquered Spain and Portugal, and in 1814, the Treaty of the Ardennes was signed. With no hope to recover their European thrones, the kings established new kingdoms in their old colonies. In this way, the Kingdom of the Rio de la Plata initiated its existence.