Ῥοδογάϊσος, (according to Zosimus), invaded Italy at the head of a formidable host of barbarians, in the reign of the emperor Honorius. The swarm of barbarians collected by him beyond the Rhine and the Danube amounted to 200.000, or perhaps to 400,000 men, but it matters little how many there were. This formidable host was composed of Germanic tribes, as Suevians, Burgundians, and Vandals, and also of Celtic tribes. Jornandes calls Radagaisus a Scythian ; whence we may infer that he belonged to one of those Germanic tribes which, at the beginning of the fifth century, arrived in Germany from their original dwellings north of the Euxine, especially as he is sometimes called a king of the Goths. In A. D. 406 Radagaisus invaded Italy, destroyed many cities, and laid siege to Florence, then a young but flourishing city. The safety of Italy had been entrusted to Stilicho, who had been observing his movements with a small army, consisting of picked soldiers, and reinforced by a contingent of Huns and Goths, commanded by their chiefs Huldin and Sarus. Stilicho now approached to save Florence if possible, and to do his utmost for the preservation of Rome. The barbarians were entrenched on the hills of Faesulae in a strong position, but Stilicho succeeded in surrounding those barren rocks by an extensive line of circumvallation, till Radagaisus was compelled, by the failure of food, to issue forth and offer battle. He was driven back within his own lines, and at last capitulated, on condition that his own and his people's lives should be saved. But Stilicho violated the agreement; Radagaisus was put to death, and his warriors were sold as slaves. This miserable end of the barbarians and the fortunate delivery of Florence was attributed to a miracle. (Zosim. v. p. 331, ed. Oxon. 1679; Jornand. De Regn. Success. p. 56, ed. Lindenbrog; Oros. 7.37 Augustin. de Civ. Dei, 5.23; Marcellin. and Prosper, Chronic.)
[W.P]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890