I want to ask the reason an old noble family from Ukraine chose their last name. Is it accepted here? If no, where else can I ask my question?
2 Answers
That seems to me like it would be on-topic.
However, you have to understand that we don't have perfect, or sometimes even very good, knowledge about past events. Its quite likely we don't know the answer to that, and the way that's phrased seems to assume there's a simple answer.
So it might be better to ask what is known and/or what information we might have about the rationale. If the answer is simple (I haven't looked into it), that could still be given, but this leaves people space to say what the various historical theories are, what little is known, or even in the worst case, that we have no clue ("...and here's why:").
I agree with T.E.D. in that name changes and choices of names are on-topic if they represent historical matters and can be answered using historical methods. For example, the circumstances surrounding former US president Bill Clinton's dropping of his birth last name Blythe is reasonably well-documented, as well as the British Royal Family's adoption of the royal house name of Windsor. We could also tackle questions on the historical trend of immigrants to various countries adopting (or not) localized versions of their names upon immigration (e.g. Petrovich to Peters or Janssen to Johnson), but probably could not comment on the motivations (or lack thereof) of your specific non-notable ancestor who may or may not have changed their name at some point.