Which two Roman assassins are chewed in Lucifer's side mouths?

The two Roman assassins chewed in Lucifer’s side mouths are Brutus and Cassius.

In Dante’s Inferno, Lucifer is trapped at the center of the frozen ninth circle of Hell. His three faces and three mouths parody the Christian Trinity, while his six useless wings beat the air and create the icy wind that keeps the lake frozen.

The side mouths punish Marcus Junius Brutus and Gaius Cassius Longinus, who helped assassinate Julius Caesar in 44 BC. Dante treats Caesar as the divinely appointed founder of the Roman imperial order, so their murder represents treachery against earthly government. The central mouth contains Judas Iscariot, whose betrayal of Christ is judged even worse.

A common mix-up is to name Judas alongside the two Romans when the question asks specifically for the assassins. Dante’s arrangement links political betrayal and religious betrayal: Brutus and Cassius occupy the side mouths, while Judas receives the most severe torment in the central one.