I created it and I think it is, but I want an opinion from someone (maybe a mod?). Does this fall into the category of "Not often used" or the "Not constructive, let's toss it" category?
A general principle I go by is this: if you create a tag, you have to demonstrate that it has worth to the site, usually by adding a tag wiki.
In this case, you did add a tag wiki, which was approved. It is from this and a quick read-through of the questions that I base my opinion, which is this:
- We don't appear to have any other tags whose scope cross.
- It is a valid aspect of worldbuilding - empires are important to the politics and dynamics of a world.
- Therefore, I think this tag, although little-used, definitely has a place on this site.
(Side note: it may be little-used, but if people need a similar tag, the tag search box should bring it up.)