tribune of a praetorian cohort under Nero, was commissioned by the emperor, on the detection of the conspiracy of Piso, A. D. 65, to demand from the philosopher Seneca an explanation of certain suspicious words which he was charged with having spoken to Antonius Natalis. Silvanus himself was involved in the conspiracy; and though he was acquitted, he put an end to his own life (Tac. Ann. 15.60, and 50, 71). Orelli, in his edition of Tacitus, reads Gavius Silvanus instead of Granius Silvanus.
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