Something to bear in mind was that the southern part of modern Argentina was never actually part of the Spanish empire. They never got that far, and the Mapuche Indians were able to hold them off until the late 1800's. It was really only when the Welsh settled in Patagonia that the Argentines and Chileans began to show an interest.
In 1860 the various Mapuche tribes got together and declared their own Kingdom of Araucania and Patagonia - and appointed a frenchman as their king. The Chileans quickly moved in and deposed him, but since then the Kingdom still exists, though in exile in France. However the Kingdom predates any annexation of territory by Argentina or Chile.It also appears that the UK -at the time -recognised the Kingdom of Araucania and Patagonia as the valid controlling power.
Wouldn't it be just deserts if the UK were to start a campaign at the UN to reinstate the Kingdom as the valid government, and to award compensation to the dispossesed Mapuche peoples, who have been subject to imposed rule by Argentina and Chile since 1862 and 1880 respectively?
Kingdom of Araucania and Patagonia - Mapuche Portal - Index
Kingdom of Araucania and Patagonia - Lomwiki, the micronation encyclopaedia
Map of the Kingdom of Araucania and Patagonia
