Do you know any non-fantasy games set in this time period which is often colloquially referred to as the Dark Ages - Early Middle Ages? There are plenty of games set in Antiquity before ca. 300 AD and plenty of games set in the High and Late Middle Ages but the time period between roughly 300 -1000 AD isn't very well represented, at all.

I can't think of anything off the top of my head aside from multi-period strategy games where you pass through these centuries like Civilization, Empire Earth or Emperor: Rise of the Middle Kingdom and mods like Brytenwalda for Mount & Blade: Warband or the Viking / Norman Invasion mods for Rome: Total War.
Preferably, I'm looking for games that natively focus on the time period in question.

Looking for historical games -without- fantasy elements so that would exclude the Myth series, Banner Saga etc.

The Stronghold games are close to that time period...

There's also a Total War game that's set between 793 and 1066, Medieval: Total War.

And another set in 395 AD, Total War: ATTILA

Stronghold Crusader is based on the late 12th century which is in the High Medieval Age, and Stronghold is late 11th century up until about the 1320s - can't be much later than that considering there aren't any cannons in the game. Duc Volpe somehow got his stinky paws on a set of 15th century armor, no idea how he manages to pulled that off.

The base game of Medieval Total War as well as its sequel are set in the High Medieval Ages but the Viking Invasion add-on seems to be the closest bet for what I'm looking for indeed. Attila is definitely in the right period as well, is that game any good?
Reviews seem somewhat negative, perhaps I'll keep an eye on the Medieval Total War Collection since Viking Invasion is included in that one - a number of people are reporting crashes though in very recent reviews, seems to be a shoddy re-release that was just added to Steam last month or something, no idea.

There's Great Invasions from AGEOD/Matrix, a Paradox-style grand strategy covering the years 350-1066:

http://www.matrixgames.com/products/359/details/Great.Invasions

I haven't played this game myself, but according to reviews the game has some interesting features, but also suffers from design flaws and poor user interface. Here's one fairly comprehensive review:

http://www.outofeight.info/2007/04/great-invasions-review.html

I guess it might still be worth considering, seeing as there aren't really any alternatives. Then again, to quote the above review, "There is a great likelihood that your head will explode while attempting to play this game."

Not many. This is certainly a time period that for whatever reason, pop culture largely ignores. I would bet that most even well-educated people would struggle to accurately describe the state of the world from 200 to 1200. I know I would.

Part of Crusader Kings 2. There's an expansion that begins as early as the mid 700s. The dark ages really isn't the focus though.

Chrono Trigger has a section that's in that timeframe... and much earlier... :P

I haven't played it, but visually, Banished seems to fit that period.

Interesting find! I never heard about this game before, it does indeed look a lot like Europa Universalis. I doubt I'd have the time, energy and motivation to deal with such OCD level micromanagement, that's one reason why I currently don't play any of the Paradox games even though I find them very interesting. Something like Imperialism 2 would be more agreeable, still has a lot of depth but doesn't go crazy on detail. It's a massively interesting time period, so much untapped potential for games.
I'd love a full scale migration sim where you can play as one of the Germanic tribes (Franks, Goths, Vandals etc) or the Huns.
Or how about a Viking pillaging sim, kinda like a more large scale version of Sid Meier's Pirates with burning villages etc. Crusader Kings 2 looks very interesting though it seems a bit overdetailed to me.
Ideally, I'd like something that can be played in a more streamlined way like Civilization & Imperialism. I'm willing to sacrifice some detail for a more fluid gameplay experience. Crusader Kings seems incredibly detailed, I'm sure it's perfect if one has the time and energy. You're right, totally forgot about that! I do remember Ayla's stone age bunga bunga village a lot better though. Haven't played Banished, either. It does indeed look the part, good call. I'm missing the historical context though in that game, running an isolated village might be authentic but disconnected from the larger events of the period.

Perhaps Conquests of Camelot:
[url=https://en.wikipedia.org/wiki/Conquests_of_Camelot:_The_Search_for_the_Grail]https://en.wikipedia.org/wiki/Conquests_of_Camelot:_The_Search_for_the_Grail[/url]

edit:
Ugh, somehow missed the non-fantasy bit, sorry.

Age of Empires 2, it's one I grew up with and it's actually even gotten some recent mods and an HD re-release despite being like 20 years old now.

Nevermind the non-fantasy part in this case, that's was a great suggestion. Playing it right now. The text parser is a bit annoying, I'm speaking plain English and the characters think I'm using Moorish words -_- (see attached screenshot)

Will see how far I get with this one.

Ah, an obscure game I never even heard about, thanks for sharing! Too bad there's no English version, it does sound interesting.

Closest thing we have to that on GOG is probably King of Dragon Pass, and more remotely Cultures Northland.

Starts in the Dark Ages so yes, good mention. I almost bought Age of Empires 2 HD for nostalgia when it was 85% off during the summer sale on Steam but I passed on the offer after seeing that there was no LAN support. I remember having a lot more fun with multiplayer than with the campaigns. The campaigns in both AoE1 & 2 aren't that exciting, multiplayer is where this series really shines.

There is Rome Total War: The Barbarian Invasion, along with several mods for Rome and Medieval II Total War, along with the King Arthur games of course, although they incorporate fantasy elements. Other than that, anything featuring Vikings (such as Mount & Blade Warband: Viking Conquest) or King Arthur/Charlemagne fits the time period.

It is disappointing that the period is not better covered in games as it is a fascinating period.

It is indeed hard to understand why there are so few material on the late Roman Empire, on the great invasions or on the time of Charlemagne & successors.

I have played Great Invasions, and while of the same nature as the Europa Universalis series, it's less about micro-management. But it's not less complex and even the improved version suffers from severe balancing issues. It's one of the earliest Ageod games (actually it predates Ageod) , and like all of them has a steep learning curve.

Rome TW had a "barbarian invasion" extension covering 360-470AD. Nowadays they have Attila

If you have a budget for it, Slitherine sells Field of Glory Digital , and the extensions Legions Triumphant and Decline and Fall, together with the battle pack will give you a wide array of battles set in the period.. It's above all a computer boardgame.

As for early MA, you have Crusader Kings II with the old gods and Charlemagne extensions, and The Kings of the Dark Age

If you go back to the DOS era, you'd find references to Viking:field of conquest, or to Hammer of the Gods