He was suffect consul in the second quarter of 65 as the colleague of Aulus Licinius Nerva Silianus, replacing Marcus Julius Vestinus Atticus whom Nero forced to commit suicide.
[1] However, noting that the suffix -enus was typical of names from Picenum and the vicinity, other authorities believe that the Pasidieni were of Picentine or Umbrian descent.
Some authorities were uncomfortable with this identification, since it presumed Firmus had been adopted by a member of the patrician Licinii Nerae, which would lead to a number of problems.
The discovery of a military diploma dated to 18 June of the consulship of Nerva Silianus and Pasidienus Firmus decisively proved they were two different men.
Remy connects his lengthy tenure to the victorious campaign (in 48–49) of Gaius Julius Aquila in the Cimmerian Bosphorus against Mithridates, the former king of Bosphorus, a campaign to which Claudius and his advisers attributed exceptional importance by awarding excessive rewards to the victorious generals.