When Commodus' behaviour became increasingly erratic throughout the early 190s, a conspiracy led to his assassination on 31 December 192. The plot was carried out by the Praetorian prefect Quintus Aemilius Laetus, Commodus' mistress Marcia, and his chamberlain Eclectus. After the murder had been carried out, Pertinax, who was serving as urban prefect at this time, was hurried to the Praetorian Camp and proclaimed emperor the following morning. His short reign (86 days) 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.