This time it's the region of Catalonia in Spain. While Scotland's vote proceeded with the blessing of the British government, Spain's vote promises to be more fractious.
Here are a few things about the vote:
1. Catalonia is a rich autonomous region in Spain's north-east, on the border with France. Its inhabitants, called Catalans, number 7.5million. Its capital is Barcelona, the second-largest city in Spain.
2. With a distinct language and culture, many Catalans have long complained they get a raw deal from the government in Madrid, which decides how their taxes are spent.