Monuments are built to revere Macrinus at a high point of his popularity.

The grand tetrastyle Capitoline Temple in Volubilis is erected to honor him in 217.

Meeting the Parthians in battle during the summer of this year, Macrinus achieves a costly draw near the town of Nisibis and as a result is forced to enter negotiations through which Rome is obliged to pay the enormous indemnity of two hundred million sesterces to the Parthian ruler Artabanus IV in return for peace.

However, Macrinus displays some financial farsightedness when he revalues the Roman currency.

He increases the silver purity of the denarius from 51.5% to 58%—the actual silver weight increasing from 1.66 grams to 1.82 grams.

Nevertheless, Macrinus' reluctance to engage in warfare, and his failure to gain victory over even a historically inferior enemy such as the Parthians causes considerable resentment among the soldiers.

This is compounded by him curtailing the privileges they had enjoyed under Caracalla and the introduction of a pay system by which recruits receive less than veterans.

After only a short while, the legions are searching for a rival emperor.

His popularity also suffered in Rome.

Not only has the new emperor failed to visit the city after taking power but a late-summer thunderstorm causes widespread fires and flooding.

Macrinus' appointee as urban prefect proves unable to repair the damage to the satisfaction of the populace and has to be replaced.