Year of the Five Emperors
The Year of the Five Emperors refers to AD 193, in which five men claimed the title of Roman emperor: Pertinax, Didius Julianus, Pescennius Niger, Clodius Albinus, and Septimius Severus. This year started a period of civil war when multiple rulers vied for the chance to become emperor.
Source: Wikipedia — Year of the Five Emperors (CC BY-SA 4.0)