General update 

I've expanded the article in general and corrected some of the English, namely some literal translations and "false friends". For example, it was written that Castelao was an "universalist", when Universalism in English is a religion (wiki it ;)). The correct translation from the Galician universalista / universalismo when speaking about politics is "internationalist / internationalism", and so on.

Also, I have serious doubts about what's said in reference to the translations of his works... Only a handful of his short stories are translated into English as far as I know, and I don't think there's many translations around in other languages. Even his key work Sempre en Galiza is only available in the original (I think it's only now that someone is starting to translate it, into English).
Most of the info I've added is from Sempre en Galiza, as this book gives lots of bibliographical information.