I was thinking about how we can use superiour features of Stackexchange to attract those people to this site.
I made already the suggestion to tag historically, not only thematically.
Another thing i would like to discuss/suggest is putting a timestamp on every question (where we know exactly the century).
So, e.g. every question on WW1/2 gets tagged with a
20th timestamp (for conventions on historical dating look here.
Century means per definition a time frame of 100 years, while notations like BCE-CE lack this implicit time range. Imho a century is a good historical scale and well suited for tagging.
A Problem arises for dates BC, either negative centuries or we leave out tagging with centuries there and refer to epoch as suggested in my first link.
This could get a quite nice tool for prof. experts/students but of course also enthusiasts like most here to search easily what happend within a specified time frame and region by using powerful stackexchange search syntax, e.g.
+[18th]+[19th] napoleon battle
Using tag-synomys we could match distinct questions then with epochs/eras, e.g.
+[middle ages] +battle (all tags from 4th - 15th) to see all battles in a epoch. Neither Google or Wikipedia can do similar and it would be unique selling proposition.
Wikipedia has a good list of names of distinct periods and correlating centuries