The Latin word dux was adopted to designate a political and military figure that had no exact equivalent in the classical world, thus redefining the concept of "duke" in a form that would continue to develop in later centuries.
At that time the Lombards were nomads, forming homogeneous groups and compact families originating from the same noble clan, and able to organize themselves into quotas with military functions: the Fare.
The figure of the Lombard Duke encompassed a mixture of military, noble, sacral (invested by the king, attended his "charisma"), political, judicial, and administrative elements.
Since the first city conquered by Alboin in 568, Cividale, a duke was appointed in any militarily significant urban center, with a mandate to lead the Lombards warriors settled in nearby areas "in Fara" against any enemy threats.
The only exception, the Duchy of Benevento, was soon elevated to the rank of principality (though weakened by secessions), retaining its autonomy and indeed playing an important political role until the arrival of the Normans in the 11th century.