An Alternate History where the British Invasions of the River Plate (1806-1807) were successful. The British integrate the Viceroyalty of the Río de la Plata as a Colony. The lands east and North of the Paraná River (Platinean Mesopotamia) were given to Portugal, a British Ally. Salta managed to remain as a Spanish Colony and was incorporated into the shortly lived Viceroyalty of Upper Peru, thanks to Spanish Help from Peru and Upper Peru. Paraguay, meanwhile, secured their independence, but fell into British and Portuguese influence.
Later, Simón Bolivar started his Liberation Campaign, however due to San Martín never coming back from Spain to help the Platinean Independentists, he had the task of liberating all of Spanish South America. When Peru and Upper Peru were liberated, the Chilean Military declared independence and took control of the former General Captaincy of Chile.
The Republic of Entre Rios gained independence around 1825 from the Brazilian Empire, and became a Unitary State (In contrast with OTL in which Entre Ríos was one of the main supporters of Federalism).
The Rio de La Plata Colony gained Dominion Status in 1910, along with South Africa.
This Colony received many British Colonists, especially in the Southern Provinces, so it has a very mixed population, and is mostly Bilingual.
The Dominion helped during WW1 against the Central Powers, sendind troops to Europe and Africa, and its small Fleet helped the British in the Falkland Islands against the German fleet.
The Dominion would eventually gain Independence after WW2 continuing to be a member of the Commonwealth and a Crown Realm.
