In the spring of 190, Rome was afflicted by a food shortage, for which the official actually in charge of the grain supply managed to lay the blame on Cleander. At the end of June, a mob demonstrated against Cleander during a horse race in the Circus Maximus: he sent the praetorian guard to put down the disturbances, but Pertinax, who was now City Prefect of Rome, dispatched the "Vigiles Urbani" to oppose them.