COTTII REGNUM, a district in Liguria, Italy, including much of the important road over the pass (6,1 19f t.) of the Alpis Cottia (Mont Genevre) into Gaul. This route was certainly in use about too B.C. (See PUNIC WARS.) In 58 B.C. Caesar met with some resistance on y crossing it, but afterwards entered into friendly relations with Donnus, the king of the district ; he refers to it as the shortest route. Donnus's son Cottius erected a tri umphal arch at his capital Segusio, the modern Susa, in honour of Augustus. Under Nero, after the death of the last Cottius, it became the province of "Alpes Cottiae," governed by a pro curator Augusti.