I’d say it’s mainly because it sounds cool. I love the Assyrians, and they were really innovative in how they formed and administered their empire, but the idea of ‘empire’ is loose enough that ‘first’ isn’t super meaningful without being in a pretty narrow, specific conversation.

I don’t have a go-to definition of ‘empire’ (maybe something about a single center administering multiple self-sufficient areas? I’m definitely a minimalist for this sort of thing). I’m not conversant in all the literature about ‘empire’ (especially any intellectual history, or how the politics of scholars affects the word’s usage/definition), but I very much enjoyed Stoler and McGraanahan 2007’s introduction to their edited volume (“Imperial Formations”) about empire.

They try to sum up the basic pros and cons of using ‘empire’ as an analytic frame. First, that the modern understanding (still generally an ‘I know it when I see it’) is heavily based on European colonial efforts, which were in turn intentionally compared (both at the time and now) to the Romans. The Romans are still the empire par excellence, though since they invented the word we now use, they have a bit of an unfair advantage. However, since so many polities conceive of themselves as ‘empires’ and this impacts their policies, it would be ridiculous to pretend the word doesn’t exist just because a stable definition is tricky. There is a lot of good discussion about borders, foreignness, ideology, and more that I can’t do justice to here. But overall, the goal is to look very closely at how, at a given time, place, and social setting, states make policy. We shouldn’t try to shoehorn complex and ever-changing formations into a definition, but we should recognize that large scale ideologies and processes matter to daily life, and to understand the complex interactions involved in forming and being in an empire.

To go back to the Assyrians for a brief example: they were a single polity that conquered others, bringing them in to an integrated economic system; they began the process with client states and then moved to legally and culturally integrate subject peoples to an intentionally constructed ‘Assyrian’ identity; they built road and hydrological systems on a previously unknown scale; they forcibly displaced an immense number of persons. They were an empire, unquestionably. The scale of their actions is likely why (with not unjustifiable reason) the Wikipedia contributor labeled them as the ‘first’. But it matters less that they built twice as many dams as the Kassites, say; it is much more interesting that after a century of limited territorial expansion, they shifted to direct control of subjugated people and that they saw massive agricultural works as integral to their State and the continued integration of people who had recently been forced to leave their home at swordpoint. What they did, why they did it, and to whom they did it, is more fascinating than just doing it ‘first’.