The Ustashe got the Goth part wrong, similar to Serbs who claim how their ancient empire stretched all the way to the Volga.
Genome stuff is interesting. What nation isn’t genetically a melting pot? Linguistic evidence needs to be sanely appraised, too. In the New World Africans speak English, French, Portuguese and Spanish ... Onomastically it’s plain that Croats with names like JOVANCIC in Slavonia are Croatized Serbs (Sokci). The name of the Serbian area above Sarajevo, Romanija, says plenty.The Hungarian name Kovacs ~ Kovats ‘Smith’ is unmistakabnly Slavic, whether Slovak or Serb. CeauceSCU (-ski), too. Romantics, to be kind, in all tribes, believe in nonsense. Venetians and Slovenes wannabe the descendants of the VENETI. Serb Romantics claim Serbs are the oldest people in the world; in Serbia this has provoked a satire “The Serbs Before and After Adam”. US “diplomat” Frank Wisner (the man from Enron)runs around reciting a propos of Kosovo the silly chauvinist claim that Albanians are the Urvolk of the Balkans. Marco Polo is claimed as a Croat. Scots of Galloway will be insulted if told they are a mix of Norse (well, OK) and Irish —oh gawd, No!. Even the great Cavalli-Sforza refers to “Yugoslav” as a homogeneous geneetic area. In Dubrovnik the patron saint is Blaise. If the place were Croatian at bottom,. the name would be “Blazej”, but it’s “Sveti Vlaho” —Serbian.
The Danube is not the Volga, Dio. I’m keen to see your bibliography on Serb claims of an empire extending to the Volga. Serbs joke about Austria-Hungary’s WMD of “Greater Serbia” as “Srbija do Tokija” Serbia all the way to Tokyo!” —
See Encyclopedia Americana, Edition 1993, Vol 24, page 572: “[During Tsar Stefan Dushan’s reign] the Serbian empire stretched from the Danube to the Gulf of Corinth and from the Aegean to the Adriatic. The economic and cultural progress of Serbia at this period was above the average European level. Many monasteries of Serbian-Byzantine architectural style - including Studenica, Decani and Grachanica - founded by several kings, bear witnesss to this highly developed Serbian culture. Dusan’s code of laws (Zakonik), formulated in 1349-1354, shows the advanced social structure of the Serbian state.”-—
The Serbian Empire 1346 was bordered by Byzantium, Bulgaria, Hungary and the Adriatic. That’s where Dubrovnik is. Croatia was a few counties around Zagreb a.k.a. Agram and belonged to Hungary. After Greater Croatia’s phoney “Vaterland War” of of the 1990s — drafted and executed by Bill Clinton’s MPRI, with Austrian, Slovenian, German, Vatican, and Saudi collusion — Art restorers in Dubrovnik found Byzantine painting beneath the later Catholic, not Croatian, but Italian murals.
See excellent (and cheap) historical atlases by Colin MacEvedy...