Legio V Illyrica was a legion of the Roman Army which was raised by Servius Servilius Cornutus in Narona, Illyricum in 41 BC. The legion was loyal to Octavian during the civil wars of the Second Triumvirate, and it was raised to protect the Adriatic coast from the Balkan tribes to the northeast, the Thracians to the east, and Antony's Rome to the south. When war broke out with Mark Antony, Legio V Illyrica participated in the Greek campaign of the war, capturing Thessalonica before marching east, through Thrace, and into Anatolia, where Legio V Illyrica captured Nicomedia, Pessinus, Pergamum, and several other eastern cities which had remained loyal to Antony during the conflict.