Pertinax Emperor of the Roman Empire from 1 January 193 to 28 March 193.
Publius Helvius Pertinax Augustus was Roman Emperor for the first three months of 193.

As the successor to the assassinated Commodus, he was the first to serve as emperor during the tumultuous Year of the Five Emperors.

He attempted to institute several reform measures, and one of those reforms - the restoration of discipline among the Praetorian Guards - led to conflict that eventually culminated in Pertinax's murder by the Guard.

Following the murder, the Guard auctioned off the imperial throne to the highest bidder - the wealthy senator Didius Julianus. This led to a civil war, in which the general Septimius Severus was ultimately successful.
(1) Pertinax
An AR Denarius struck 193 AD in Rome
Obverse: IMP CAES P HELV PERTIN AVG, Head of Pertinax facing right, wearing laurel wreath

Reverse: AEQVIT AVG TR P COS II, Aequitas standing facing left, holding scales and cornucopia

Diameter: 19 mm
Die Orientation: 12 H
Weight: 2.69 g
Commodus was assassinated on New Year's Eve of 192 AD, Pertinax who at the time was serving as urban prefect (I suppose the comparison to modern times would be sheriff) was installed as Emperor on January 1st of 193. The Praetorian Guard (the comparison to modern times here I would say is the Secret Service) expected a large bribe for this gift and when he only paid half and tried to reform them they assassinated him, his reign lasting all of 87 days.

Thus began the "Year of Five Emperors."
RIC IV Pertinax 1a
An AR Denarius struck AD 193 in Rome
Obverse: IMP CAES P HELV PERTIN AVG, laureate head right

Reverse: AEQVIT AVG TR P COS II, Aequitas standing left holding scales and cornucopiae

Diameter: 18 mm
Die Orientation: 7 H
Weight: 3.18 g
No notes for this coin
RIC 1a; RSC 2