The Carni are usually considered a Gaulish tribe, although some associate them with the Venetic peoples, a group closely related to but probably distinct from the Celts.

Their area of settlement isn't known with precision.

Strabo confines them to the mountains, while Ptolemy assigns them two cities near the Adriatic coast.

They are likely eponymous of the regions of Carnia, Carniola and Carinthia.

The first historical date related to the arrival of the Carni is 186 BCE, when some fifty thousand Carni, composed of armed men, women and children, descend from the northeast corner of transpadane Italy towards the plains (in which they previously used to winter) and on a hill they establish a stable defensive settlement, Akileja, situated at the head of the Adriatic at the edge of the lagoons, about ten kilometers from the sea, on the river Natiso (modern Natissa).