Short answers, pulled from the story.
The Year of the Five Emperors refers to AD 193, when five men claimed the title of Roman emperor within the same year: Pertinax, Didius Julianus, Pescennius Niger, Clodius Albinus, and Septimius Severus. The year began with the assassination of Commodus and ended with Severus emerging as the empire's dominant ruler.
The five claimants were Pertinax, Didius Julianus, Pescennius Niger, Clodius Albinus, and Septimius Severus. Most historians count Severus and Albinus as two separate emperors even though they ruled simultaneously for a time.
The Year of the Five Emperors began after the assassination of Emperor Commodus on New Year's Eve 192. Three nobles, Eclectus, Marcia, and Laetus, had Commodus strangled, fearing he would target them next, and the assassins named Pertinax the new emperor.
Didius Julianus became emperor by purchasing the title from the Praetorian Guard after Pertinax was killed, outbidding Pertinax's father-in-law, Sulpicianus. He was executed on the 1st of June by Septimius Severus, who reached Rome first.
Septimius Severus defeated Pescennius Niger at the Battle of Issus in 194 and defeated Clodius Albinus at the Battle of Lugdunum in 197. These two victories left Severus as the empire's sole emperor and founder of the Severan dynasty.
Septimius Severus won the Year of the Five Emperors, defeating Pescennius Niger in 194 and Clodius Albinus in 197 to become sole emperor. His victory established the Severan dynasty.