Cohors prima Delmatarum milliaria equitata ("1st part-mounted double-strength Cohort of Dalmatae") was a Roman auxiliary mixed infantry and cavalry regiment. It was named after, and originally recruited from, the Dalmatae

Dalmatae

The Dalmatae or Delmatae were an ancient people who inhabited the core of what would then become known as Dalmatia after the Roman conquest - now the eastern Adriatic coast in Croatia, between the rivers Krka and Neretva...

 (or Delmatae), an Illyrian-speaking people that inhabited the Adriatic coastal mountain range of the eponymous Dalmatia

Dalmatia

Dalmatia is a historical region on the eastern coast of the Adriatic Sea. It stretches from the island of Rab in the northwest to the Bay of Kotor in the southeast. The hinterland, the Dalmatian Zagora, ranges from fifty kilometers in width in the north to just a few kilometers in the south....

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The ancient geographer Strabo

Strabo

Strabo, also written Strabon was a Greek historian, geographer and philosopher.-Life:Strabo was born to an affluent family from Amaseia in Pontus , a city which he said was situated the approximate equivalent of 75 km from the Black Sea...

 describes these mountains as extremely rugged, and the Dalmatae as backward and warlike.