His career before he became emperor as it is documented in the Historia Augusta has been confirmed in many places by existing inscriptions. The son of a freedman Helvius Successus, originally Pertinax made his way as a grammaticus or teacher of grammar, but he eventaully decided to find a more rewarding line of work and through the help of patronage he was commissioned an officer in a cohort. In the Parthian war that followed, he was able to distinguish himself, which resulted with a string of promotions, and after postings in Britain and along the Danube, he served as a procurator in Dacia. He suffered a setback as a victim of court intregues during the reign of Marcus Aurelius, but shortly afterwards he was recalled to assist Claudius Pompeianus in the Germanic wars. Afterwards he was governor of the provinces of Upper and Lower Moesia, Dacia, and Syria, as well as receiving the honor of a suffect consulship around the year 175.
In the decade of the 180s, Pertinax took a role in the Roman Senate until the praetorian prefect Perennis forced him out of public life. He was recalled after three years to govern Britain, whose army at the time was in a state of mutiny. He quelled the unruly soldiers, and returned in honor to Rome. He served as proconsul of Africa in 188 - 189, and followed this term of service with the prefecture of Rome -- and a second consulship as ordinarius with the emperor as his colleague. He was serving as urban prefect when Commodus was assassinated by his own household.
Pertinax's short reign was an uneasy one. He attempted to emulate the restrained practices of Marcus Aurelius, and made an effort to reform the alimenta but he faced antagonism from many quarters. Ancient writers detail how the Praetorian Guard expected a generous donative on his ascension, and when they were disappointed, agitated until he produced the money, selling off Commodus' property, including the concubines and youths Commodus kept for his sexual pleasures. He narrowly averted one conspiracy by a group to replace him with Falco, but a second conspiracy ended with his assassination by members of the Praetorian Guard. Pertinax must have been aware of the danger he faced by assuming the purple, for he refused to imperial titles for either his wife or son, thus protecting them from the aftermath of his own assassination.
Following his entrance into the city of Rome, Septimius Severus recognized him as a legitimate emperor, and not only pressured the Senate to provide for him a state funeral, but for some time held games on the anniversary of Pertinax's ascension and his birthday.
Commodus (180 - 192)
Septimius Severus (193 - 211)