COTTII REGNUM, a district in the north of Liguria, including a considerable part of the important road which led over the pass (6119 ft.) of the Alpis Cottia (Mont Genèvre) into Gaul. Whether Hannibal crossed the Alps by this route is disputed, but it was certainly in use about 100 B.C. (see Punic Wars). In 58 B.C. Caesar met with some resistance on crossing it, but seems afterwards to have entered into friendly relations with Donnus, the king of the district; he must have used it frequently, and refers to it as the shortest route. Donnus's son Cottius erected the triumphal arch at his capital Segusio, the modern Susa, in honour of Augustus. Under Nero, after the death of the last Cottius, it became a province under the title of "Alpes Cottiae," being governed by a procurator Augusti, though it still kept its old name also.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)