Piso was certainly praetor before 135, as the "Lex Villia" required a three-year wait between holding two magistracies (and Piso was consul in 133). The dominant opinion among modern scholars is that Piso served as praetor in Sicily in a year between 138 and 136, and he was defeated by the revolted slaves of Eunus during the First Servile War. However, knowledge of this war is very poor, and mostly comes from epitomes deriving from the lost books of Livy's "Ab Urbe Condita". The only mention of Piso as praetor in ancient sources is found in the epitome of Florus (dating from the 2nd century AD), who says that "The camps even of praetors (the utmost disgrace of war) were taken by him [Eunus]; nor will I shrink from giving their names; they were the camps of [Manlius], Lentulus, Piso, and Hypsaeus". From there, it has been assumed that Florus gave the names of the successive Sicilian praetors in chronological or reverse-chronological order between 138 and 135.