ARBOGASTE. - A Frankish general who distinguished himself during the reigns of Gratian and Theodosius, Arbogaste became *magister militum* of Valentinian II; but his excessive interference made him unpopular and led to his dismissal. A few days later, Valentinian was found dead, and Arbogaste attempted to have the *magister officiorum* Flavius Eugenius elected in his place. However, Eugenius was not recognized by the Eastern Emperor Theodosius the Great, who, after assembling an army, clashed with Arbogaste’s forces on the Frigidus River, at the foot of the Julian Alps. After fierce fighting, victory went to Theodosius (6 Sept. 394); Eugenius was beheaded, and Arbogaste took his own life.
BIBL.: G. Morpurgo, *A. e l'impero romano dal 379 al 394*, Trieste 1883; O. Seeck, *Geschichte des Untergangs der antiken Welt*, V, Berlin 1913; A. Solari, *Il rinnovamento dell'impero romano*, Milan-Rome 1940.