So the US ground still "belongs" to GB and the Indian ground still "belongs to England?
You misunderstood what I meant to say. All I am saying is that the colonists declared Independence but had to fight England for the land. In the case of Catalonia, the Catalonian Spaniards live there but it is still part of Spain because Spain occupies Catalonia and because of Spanish legislation vs Catalonia Declaration of Independence. Are you saying that Spain accepted their independence ? Or are you saying that all it takes is for a region of a country to be independent is to email Madrid the message: "Have we got news for you!"
Anything can happen but at this time Catalonia is part of Spain same as California is part of the US should they send the president a letter.
I am not familiar with the Spanish Constitution and how it provides for any Spanish regions to become independent from Spain. Basques wanted independence for a long time but Bilbao and the Vascongadas are still part of Spain.
( Am I missing something? Are the Catalonians independent or are they still part of Spain?)