(Warning: The following contains biographical information about Marvel's comic book Inhumans, and can as such be considered to contain theoretical SPOILERS for future Marvel Studios movies, as well as actual ones for past comic books. Proceed with whatever level of caution that suggests to you is wise.)
Now, with Marvel Studios head honcho Kevin Feige recently revealing that the company's upcoming Inhumans movie will likely be pushed back beyond its currently scheduled July 12, 2019 release date, it's not all that surprising that the interweb is full of speculation about just what that means for the movie, and for the Inhumans' presence in the Marvel Cinematic Universe as a whole.
With the movie still at such a far remove, however — and thus capable of being completely overhauled multiple times before release — it seemed worth taking a look not at the likely content of the movie, but instead at the film's likely leading cast, and their comic book history. In other words, asking one very particular question:
Just Who Are The Inhumans, Anyway?
The short answer? They're a (sort of) alien culture, largely represented in comic book form by their royal family (above). Their strange and often grotesque appearance derives from exposure to the Terrigen mists, a right of passage through which young Inhumans are considered to reach true adulthood (and typically gain some sort of super-power). Over the years, they've alternately battled and aided some of Earth's mightiest superheroes — most frequently the Fantastic Four — in various adventures, often while being on the receiving end of widespread mistrust from human governments.
The thing is, though...
The Inhumans' History Is Actually WAY More Complicated Than That Makes It Seem
Specifically, the "short answer" has the tendency to skirt around the fact that the Inhumans aren't technically aliens. Instead, they were originally just regular homo sapiens, who found themselves being experimented on by the alien Kree. Eventually abandoned by their alien creators, the Inhumans founded their own unique culture — one based on a rigid case system, and an essentially servile underclass, the Alpha Primitives.
In other words? There's a reason the only Inhumans we've tended to see are the royal family, and it's pretty much the same reason that you only ever hear about the adventures of Medieval Kings and Queens: they were standing atop a deeply rooted feudal system that didn't allow too many other people to steal their spotlight.
Which, much like in medieval Europe, led to a whole bunch of bloody rebellions, usually led by the least reputable member of the Inhuman royal family, Maximus the Mad.
Who, barring a few brief spells of doing the right thing, has tended to be the biggest thorn in the side of his brother Black Bolt, rightful (depending on your views on monarchies, in fairness) king of the Inhumans.
Unable to speak, lest his unbelievably powerful voice destroy everything around him, Black Bolt (real name Blackagar Boltagon, because comic books are awesome) has traditionally surrounded himself with a more faithful set of royals, while tirelessly working to (once again depending on your viewpoint) either make Attilan a better place, or consolidate his rule.
What's more, while the main line-up of the royal family has remained largely unchanged over the years (above, from left, the bull-legged Gorgon, element-controlling Crystal, Black Bolt himself, his super-strong-haired consort Medusa, the weakness-finding Karnak and the aquatic Triton), their role within the Marvel universe has changed dramatically in recent times.
Where once the Inhumans were a mysterious group largely hidden from the world, they have recently replaced mutants as Marvel's go-to persecuted minority (a decision that reportedly had much to do with Fox's ownership of the X-Men's movie rights). As such, recent comic books have seen a cloud of Terrigen mist travel the globe, transforming humans into Inhumans with reckless abandon. The past few decades have also seen a loosening of both the royal family's monopoly on attention (with younger, less royal Inhumans seeing some of the spotlight) and a loosening of their association with the Earth, with the people of Attilan moving first to the moon, and then later to outer space.
And then there was a whole thing with Thanos trying to kill all 16–22 year-old Inhumans, and they eventually all wound up back on Earth.
In other words? The Inhumans are incredibly complicated, and most of what they've done in the comic books is likely to be jettison by Marvel Studios for the sake of simplicity (and due to the absence of the Fantastic Four). With the more modern "regular folk turning out to be Inhumans" plotline already proving to be a key part of Agents of S.H.I.E.L.D, it seems likely that either that — or the group's extraterrestrial origins — will be the arena in which we see the royal family explored, whenever they eventually arrive.
Though, that being said, here's hoping their giant teleporting dog, Lockjaw, makes it in no matter what.
After all, who doesn't love Lockjaw?