Pertinax

Pertinax (or Publius Helvius Pertinax, lived 1 August 126—28 March 193 AD, ruled 1 January 193—28 March 193 AD) was a Roman emperor who succeeded Commodus during a year that would see five Roman emperors come and go (the year of the five emperors). Pertinax instituted several short-lived reforms, including restoring discipline among the Praetorian Guard. This led to resistance and culminated in his assassination by the Praetorian Guard.