Praetorian Guard
At the death of Nerva, at the beginning of 98, Trajan executed the remaining Praetorian prefect and his partisans. Trajan returned to Rome from the Rhine, probably accompanied by the new unit of "equites singulares Augusti". The Praetorian Guard had participated in the two Dacian Wars of Trajan (Dacian Wars 101–102 and 105–106). The Praetorian Guard served in the last campaign of Trajan against the Parthians of 113–117.