I don't have statistics to back me up here, but as a regular browser of /r/askhistorians I am struck by the high number of questions dealing with medieval Europe and the Roman Empire (or Republic). It seems that these two (admittedly quite vast) topics take up more space on this sub than any other combination of time and place. This suggests to me that, at least on reddit, these two topics have, if not an outsized place in public memory and amateur inquiry, then at least a major one. What trends in education, popular culture, and public memory do you think contribute to this dominance?
1. Demographics. Basically the fact it is an English site at Reddit means it is dominated by internet users from the Anglosphere (specially the United States) that are mostly male, mostly white, mostly young adults in their 20s, late 10's or early 30's, with the only distinctive difference that /r/AskHistorians users have much more formal studies than the average.
2. In the census we notice that the 70% answered that were interested in Western Europe History, the highest answer rate. This is easy to identify about why: people wants to know the history they identify directly as their own, their own roots. For example right now in the front: 7 questions are unrelated, but 11 questions are directly about the British Empire or US history and 7 about their previous political/cultural entities connections. The Roman Empire is also popular due to this: since the United States and the British Empire didn't exist earlier, since none of the Germanic kingdoms which survived to the modern times didn't exist earlier (aside a brief overlap with the Franks), people feels the urge to seek something that coincides with their ideas of self identity, and the Roman Empire is the closer thing they can find when backtracking that far ago.
3. European Medieval history is popular due to a combo of school curriculum (impulsed by nationalist identity rethoric which backtracks their culture to the medieval times), the geek/gamer demographic tendency of many Reddit users which makes them used to videogames, shows and stuff inspired in the medieval times, and war. Guys are often much more interested in war topics (result of advertising, cultural traits, historical reasons, maybe even biology - controversial -), and the medieval times often features a ton of highly varied millitary history into them.
4. There are also other popular topics in this place anyway, starting with Hittler/Nazi questions, which I feel are mostly the result of a poor education about them: in school for example "WWII started due to Hittler, he is the bad guy, end" rethoric is pretty common, but that also leaves much more questions unanswered than answered at the end.
I’d be curious to know too if there is a “Game of Thrones” effect, as I noticed there seems to be a lot of questions asked in relation to tv tropes.