Duuuuude, hate to say it, but the core assumption here is drastically wrong. The recording of history never died out in Europe like you are implying. There are plenty(not as many as we'd like, but still) of chronicles that cover the 'dark ages' from different areas.

In any case, the term 'Dark Ages' is incredibly fraught. It's generally understood now that there wasn't really that much 'Dark' about it - instead Renaissance writers skewed some of the narrative towards seeing the end of Antiquity as this great coming of darkness, so that their utilising of classical ideas would appear that they were bringing back the light.

What even do we call the 'Dark Ages'? The fall of Rome in 400s until some undefined date in the 11th century? Certainly there was instability, and power wasn't concentrated the way it had been during Rome, but not only were there centers of learning, science, writing etc. Elsewhere (like Constantinople, Córdoba, Baghdad, etc.) but it's not like Western Europe dropped off the map. Indeed the Carolingian Empire united much of Western Europe during this time frame, and initiated a 'renaissance' of sorts in terms of writing, art, and education.

If you're interested in this time period I really encourage you to dive a little deeper than the surface assumptions that are so often thoughtlessly thrown around. It's an absolutely fascinating time as political structures shift, new ideas and developments are made, and much more.

I'll conclude with this - while there may be some areas that lack extensive sources during the Early Middle Ages, this doesn't mean it's 'Dark'. Indeed as archaeology, new technology and genetic tracing move forward we are learning more every day, about things from the Vikings to Charlemagne. I encourage you to dive in and discover more!

Dwyer, John C., Church history: twenty centuries of Catholic Christianity, (1998)

Syed Ziaur Rahman, Were the "Dark Ages" Really Dark?

Franklin, James (1982). "The Renaissance Myth". Quadrant.

Norman F. Cantor, The Medieval World 300 to 1300