By now, many of you are likely aware of the existence of History of Science and Mathematics Stack Exchange, which started up a year and a half ago and is still going strong in the beta stage. Mathematics is the most popular topic there; 383 questions have the mathematics tag as of today, more that double the next most popular category. They constitute about 36.48% of the site's 1,050 questions.
However, the history of mathematics is also still on-topic on Mathematics; currently, 1,452 questions have the math-history tag. However, some math history questions end up being migrated to HSM, which I, as a moderator there, receive, edit, and check for on-topic-ness. Migrations do happen; since its inception, HSM has received 18 questions from Mathematics and sent 2 others.
This is, as you can imagine, a little inconsistent, which is the first part of why I bring this up. Which questions stay on Mathematics, and which ones go? There's always some subjectivity when it comes to migrations, it could be argued, and 18 questions is insignificant, compared to the roughly 300 math-history questions asked over the past year on Mathematics.
What worries me is that people seem to have very strong opinions about whether the history of mathematics is on-topic on Mathematics Stack Exchange. That would be okay, were it not for the fact that these opinions seem to be polar opposites a lot of the time. This seems to confuse some newer posters - it certainly does on other sites. This is the second part of why I brought up this discussion.
The gist of this is that I'd like some sort of consensus as to whether or not the history of mathematics should be on-topic on Mathematics Stack Exchange. That way, either questions can stop being migrated to HSM unless the poster requests so, or they can be decisively marked as off-topic, closed as such on Mathematics, and sent over to HSM; the latter would also include editing the tour and help center, which say that the history of mathematics is on-topic.
Should questions about math-history be on-topic on Mathematics Stack Exchange?
For related reading, see http://meta.math.stackexchange.com/q/19699/170257, http://meta.math.stackexchange.com/q/20356/170257, and http://meta.math.stackexchange.com/q/17321/170257, as well as Should Math SE seed HSM with some history of mathematics questions? on HSM meta.