Caracalla and rise of Macrinus Macrinus' predecessor Caracalla was murdered on April 8, 217, during a period of war with the Parthians, near Carrhae while traveling en route to visit a temple. His murderer was Justin Martialus, a soldier who was incensed after being declined the rank of centurion. Martialus was himself cut down by Caracalla's German Guards immediately afterwards, a convenient fact for Macrinus, at the time a praetorian prefect, who was involved in the assassination. One reason for Macrinus to have intrigued against Caracalla was out of fear for his own life. A story documented by the Roman writer Herodian and supported by some later historians details the events leading to Caracalla's death. The story goes that Macrinus, in the course of his employment, was often tasked with reading dispatches sent to Caracalla for him. One such dispatch detailed a prophecy, perhaps fabricated, from the oracle at Delphi suggesting that Macrinus was destined to kill Caracalla and succeed him as emperor. In the immediate aftermath of Caracalla's death, Adventus was selected to serve as emperor, but he declined the position due to his old age. The army then chose Macrinus; they had no feelings of 'love or esteem' towards him, but there was no one else competing for the position. The army proclaimed Macrinus as emperor three days after the death of Caracalla, and named him Augustus. The results were applauded by the Senate at first, who were glad to be rid of the former emperor. But tradition held that the emperor could only be selected from among the Senate; moreover, Macrinus was a member of the equestrian class, the lower of the two aristocratic classes. These disadvantages led the Senate to severely scrutinize his every action. Their opposition, however, was not backed by any actual power. The military at the time was concentrated against the Parthians in the area around Edessa (modern Şanlıurfa, Turkey), so there was no force anywhere in the Empire that could contest the status of Macrinus. As the new emperor, Macrinus had to deal with the major threat of the Parthians, with whom Rome were currently at war. An indecisive battle at Nisibis is cited as a reason for the opening of peace negotiations. Negotiations may have been favourable for both sides; Rome was being threatened by Armenia and Dacia, and the Parthians were far from home and low on supplies. The settlement,