TREBA or TRE´BIA.
1. （ Eth. Trebias, ātis: Trevi), a municipal town of Umbria, situated at the western foot of the Apennines, between Fulginium and the sources of the Clitumnus, about 4 miles from the latter. It is mentioned by Pliny among the municipal cities of Umbria, and its name is found in an inscription among the xv Popnli Umbriae:in both these authorities the name of the people is written Trebiates. The Jerusalem Itinerary, which places it on the Via Flaminia, 4 miles from Sacraria (at the sources of the Clitumnus) and 5 from Fulginium, writes the name Trevis, thus approximating closely to the modern name of Trevi. The modern town is still a considerable place standing on a hill which rises abruptly from the valley of the Clitumnus. (Plin. Nat. 3.14. s. 19; Itin. Hier. p. 613; Orell. Inscr. 98).
2. （Τρήβα,Ptol.: Eth. Trebanus: Trevi), a city of Latium. in the upper valley of the Anio, about 5 miles from the sources of that river and 10 above Subiaco. It is mentioned both by Pliny and Ptolemy, as well as by Frontinus, who calls it Treba Augusta (Plin. Nat. 3.5. s. 9; Ptol. 3.1.62; Frontin. de Aquaed. 93); and in an inscription, which proves it to have been a town of municipal rank under the Roman Empire. (Orell. Inscr. 4101.) But its name is not mentioned in history, and it was apparently never a place of importance, for which its secluded position is alone sufficient to account. The ancient name and site are retained by the modern village of Trevi, a poor place, surrounded on all sides by lofty mountains. [E.H.B]