The Legio duodecima Fulminata ("Thunderbolt Twelfth Legion"), also known as Paterna, Victrix, Antiqua, Certa Constans, and Galliena, was a legion of the Imperial Roman army. It was originally levied by Julius Caesar in 58 BC and which accompanied him during the Gallic Wars until 49 BC. The unit was still guarding the Euphrates River crossing near Melitene at the beginning of the 5th century. The legion's emblem was a thunderbolt (on a shield fulmen). In later centuries it came to be called commonly, but incorrectly, the Legio Fulminatrix, the Thundering Legion.
The Twelfth legion, as it is perhaps better known, fought in the Battle against the Nervians, and probably also in the Siege of Alesia. The Twelfth fought at the Battle of Pharsalus (48 BC), when Caesar defeated Pompey. After Caesar won the civil war, the legion was named Victrix, and enlisted in 43 BC by Lepidus and Mark Anthony. Mark Anthony led the Twelfth, renamed XII Antiqua during his campaign against the Parthian Empire.
During the latest part of Augustus' principality, XII Fulminata served in Syria, camping at Raphana. They also were the Lost Legion in Syria.
In the East, King Vologeses I had invaded Armenia (58), a client kingdom of Rome. Emperor Nero ordered Gnaeus Domitius Corbulo, the new legatus of Cappadocia, to manage the matter, and Corbulo brought the IV Scythica from Moesia, and with III Gallica and VI Ferrata defeated the Parthians, restoring Tigranes VI to the Armenian throne. In 62, IV Scythica and XII Fulminata, commanded by the new legate of Cappadocia, Lucius Caesennius Paetus, were defeated by the Parthians and Armenians at the battle of Rhandeia and forced to surrender. The legions were shamed and removed from the war theatre.