'Don' with a big d or little D?

Question

Thanks for the replies so far, but it's just a simple answer I require: does the title DON e.g. DON JUAN begin with a little d, e.g. don Juan, or a big D, e.g. Don Juan? The reason that I ask this is that I have read in the book, 'Correct your Spanish Blunders' by Jean Yates that the title don should always begin with a little d, but I have seen 'Don' used countless times.

Answer 1

I think Don is a nobility tittle so should be Don

Answer 2

Wikipedia has it as Don Juan

Don Juan

Answer 3

I Don't know. Sorry