Iulius Placidus was a Roman military tribune in the 1st century.
During the Year of the Four Emperors Placidus served in the staff of Marcus Antonius Primus, general in the army of Vespasian. According to Tacitus Placidus led an assault detachment to the vitellian headquarters while the capture of rome by flavian troops. Placidus detained Vitellius and tortured him to death in public.
References
Iulius Placidus Wikipedia(Text) CC BY-SA