the leader of the Marsi in the Social War, and the soul of the whole undertaking, at first endeavoured to obtain for the Socii the Roman franchise, by means of M. Livius Drusus, the celebrated tribune of the plebs in B. C. 91. He came to Rome to concoct his plans with Drusus, and remained in his house several days; and it is related by Diodorus that he subsequently marched upon Rome at the head of 10,000 men, with weapons concealed beneath their clothes, in order to extort the franchise by force, but that he was persuaded by Domitins, perhaps the censor of the preceding year, to give up his enterprise (Plut. Cat. Mi. 2; Diod. xxxvii. p. 612, ed. Wess.). With the death of Drusus the allies lost all hope of obtaining their demands peaceably, and forthwith took up arms. The history of the war which ensued is given in too confused and fragmentary a manner to enable us to follow the operations of Pompaedius Silo step by step; but all accounts agree in representing him as the most distinguished of the Italian generals. His most brilliant exploit seems to have been the defeat of Q. Caepio, whom he decoyed into an ambush; but he was unable, either by his stratagems or his sarcasms, to force Marius to an engagement (Plut. Mar. 33). After most of the allies had laid down their arms and submitted to the Romans, Pompaedius still continued the struggle. He regained Bovianum, which had been taken by Sulla, and entered this capital of Samnium in triumph (Obsequ. 116). But this was his last success. He was first defeated by Mam. Aemilius, and subsequently by Q. Metellus Pius. In the latter battle he perished, and with his death the war came to an end, B. C. 88 (Appian, App. BC 1.40, 44, 53; Diod. xxxvii. p. 539, ed. Wess.; Liv. Epit. 76; Flor. 3.18 ; Ores. 5.18; Vell. 2.16). Several writers have Popedius, and others give Sylo or Sillo as the cognomen, but Pompaedius Silo is the correct orthography.