The fabric that unites the region

What region?

It is quite difficult to define a unitary region in South East Europe with so many fault lines, left behind by former empires, with so many different languages and denominations. My point is that deep below these differences are lots of reasons for unity in the form of shared history, culture and ancestry.

I will try to use geography and its influence on human behavior, instead of looking to ever changing political boundaries. 

It has been done before by the German geographer August Zeune, credited with the Balkan Peninsula concept (in Goea 1808, as cited by Maria Todorova in Imagining the Balkans, Oxford University Press, 2009), meaning the region south of the Balkan Mountains. Now it means more than that, as Encyclopedia Britannica article shows.

Google Maps satellite view of the region

The region I'm referring to is larger region and contains:

1. Balkan Mountains and adjacent plains on both sides;
2. Dinaric Alps and Pindus Mountains and their adjacent plains (sometimes these mountain ranges are considered part of Balkan Mountain group);
3. Carpathian Mountains and adjacent plains on both sides.

For the lack of a better term I'll use the name Balkan - Dinaric - Carpathian Region or BDC on short.

BDC limits would be: 

• West: Adriatic Sea;
• South: Aegean Sea;
• East: Black Sea;
• North: The Alps and the Great European Plain.

This geographic unit had a major influence on how various waves of migration entered and dispersed in Europe from South and East. It has done so since modern humans came to claim Europe from Neanderthals. For that period see this article from Nature: Genome of 40,000-year-old jaw from Romania suggests humans interbred with Neanderthals in Europe.

Balkan - Dinaric - Carpathian region is at the crossroad of two ancient (and current) migration routes:

1. East to west - directly from Asia over the Pontic–Caspian steppe, a grassland stretching from the Danube Delta to Ural Mountains;
2. South to north - from Middle East over Marmara Sea;

Danube river provided a highway toward the center of Europe and the high mountain ranges of the Balkans and Dinarics on right/south bank and Carpathians on left/north bank directed the traffic toward north-west.

Few migrations that came to Europe mainly via BDC region: 

• Fertile Crescent population bringing agriculture;
• Early indo-european speakers;
• Celts, Goths, Huns ...

So the geography of BDC region impacted the incoming traffic, but how is that relevant for present day people and what about that unifying "fabric"?