His career before becoming emperor is documented in the Historia Augusta as well as Cassius Dio's History of Rome, and confirmed in many places by existing inscriptions.

[7][5] In the Parthian War that followed,[8] he distinguished himself, which resulted in a string of promotions, and after postings in Britain (as military tribune of the Legio VI Victrix)[9] and along the Danube, he served as a procurator in Dacia.

[10] He suffered a setback as a victim of court intrigues during the reign of Marcus Aurelius, but shortly afterwards, he was recalled to assist Claudius Pompeianus in the Marcomannic Wars.

[9] During the 180s, Pertinax took a pivotal role in the Roman Senate until the praetorian prefect Sextus Tigidius Perennis forced him out of public life.

[15] He served as proconsul of Africa from 188 to 189,[16] and followed this term of service with the urban prefecture of Rome,[17] and a second consulship as ordinarius with the emperor Commodus as his colleague.

[26] In early March he narrowly averted one conspiracy by a group to replace him with the consul Quintus Sosius Falco while he was in Ostia inspecting the arrangements for grain shipments.

[32] Pertinax must have been aware of the danger he faced by assuming the purple, for he refused to use imperial titles for either his wife or son, thereby protecting them from the aftermath of his own assassination.

[18] After Pertinax's death, the Praetorians auctioned off the imperial title; the winner was the wealthy senator Didius Julianus, whose reign would end mere weeks later with his assassination on 1 June 193.

Dio refers to him as "an excellent and upright man"[38] who displayed "not only humaneness and integrity in the imperial administrations, but also the most economical management and the most careful consideration for the public welfare".

Though describing him as a good man, Machiavelli considered Pertinax's attempt to reform a soldiery that had become "accustomed to live licentiously" a mistake, as it inspired their hatred of him, which led to his overthrow and death.

[40] Pertinax is described in David Hume's essay Of the Original Contract as an "excellent prince" possessing an implied modesty when, on the arrival of soldiers who had come to proclaim him emperor, he believed that Commodus had ordered his death.