Legio II Traiana Fortis (The strong Legion of Trajan).Participation in the Marcomannic wars of Marcus Aurelius is neither excluded nor proven. We have more certainty about the legions' role in 175, when it sided with the rebel general Avidius Cassius. His revolt, however, was unsuccessful.
Eighteen years later, II Traiana Fortis supported Pescennius Niger, the governor of Syria who wanted to become emperor. Before the decisive battle against Lucius Septimius Severus in 194, the legion changed sides and was justified in its claim that it had been Severus' "king maker".
Miniatures by A&A.
Pollard, N. and Berry, J. (2012) The Complete Roman Legions.Thames & Hudson.