TREBIA (mod. Trebbia)  , a river of Cisalpine Gaul, a tributary Tabriz and the whole of Persia . The total population of of the Padus (Po) into which it falls some 4 M. west of Placentia the place amounts to about 40,000, of whom 22,000 are (Piacenza) . It is remarkable for the victory gained on its banks Moslems and 18,000 Christians . Great Britain and all the by Hannibal over the Romans in 218 B.C . The latest investi- larger European states have consulates there . gations make it clear that Polybius's account, according to which The vilayet, of which Trebizond is the chief town, consists the battle took place on the left bank of the river, is to be preferred of a long irregular strip of coast country, the eastern half of to that of Livy (see W . J . Kromayer in Anzeiger der phil. hist. which is deeply indented and mountainous . Klasse der k . Akademie der Wissenschaften, Vienna, October 14, History.—The city of Trapezus was a colony of Sinope, but it s9o8) . Its valley is followed past Bobbio by the modern first comes into notice at the time of the Retreat of the Ten highroad from Piacenza to Genoa (88 m.) . Thousand, who found repose there .