While Dragonborn can be found throughout Europe and Asia, the greatest concentration of Dragonborn near to Rome is in Greece, most notably in Thebes, where they make up the majority of the population. They are primarily warriors but it is not unusual to see them as scholars or artisans.
Legends say that Mars caused the Dragonborn to spring from the earth when Cadmus, the founder of Thebes, planted the teeth from a dragon he had slain in the ground. The most famous of all Dragonborn-- indeed, perhaps the most famous figure in all of recorded history-- is Alexstrasza the Great, a king of the ancient Greek Kingdom of Macedonia. He spent most of his ruling years on an unprecedented military campaign through Asia and northeast Africa, and over thirty years created one of the largest empires of the ancient world, stretching from Greece to Aegyptus and into present-day Ind. He was undefeated in battle and is considered one of history's most successful military commanders, but was also tutored by the philsopher Aristopheles for the first half of his life.
Alexstrasza died abruptly, his ambition to unite the far corners of the earth under a single banner left unfulfilled, and having never chosen a mate or named an heir. In the years following his abrupt death, a series of civil wars fought over succession tore his empire apart, and Greece fractured into independent city-states, each dedicated to what they perceive to be Alexstrasza's greatest trait-- To Athens, diplomacy; to Epirus, shrewdness; and to Sparta, strength. Weakened by their petty squabbles, these city-states proved easy prey for the rising Roman Republic, which conquered them quite handily in 100 BC; they have been client states of Roma ever since.
While they can be found throughout the Republic and as far away as Ind, the greatest concentration of Dragonborn near to Roma is in Greece, most notably the city-states of Athens, Epirus, and Sparta.