Legio tertia Gallica ("Gallic Third Legion") was a legion of the Imperial Roman army founded around 49 BC by Gaius Julius Caesar for his civil war against the conservative Republicans led by Pompey. The cognomen Gallica suggests that recruits were originally from Gaul. The legion was still active in Egypt in the early 4th century. The legion's symbol was a bull.
The legion took part in all Julius Caesar's campaigns against his enemies, including the battles of Pharsalus and Munda. Following Caesar's death, III Gallica was integrated in the army of Mark Antony, a member of the Second Triumvirate, for his campaigns against the Parthians. They were included in the army levied by Fulvia and Lucius Antonius (Antony's wife and brother) to oppose Octavian, but ended by surrendering in Perugia, in the winter of 41 BC.
After the battle of Actium and Antony's suicide during Antony's civil war, the III Gallica was sent again to the East, where they garrisoned the province of Syria.
Legio was a Roman military camp south of Tel Megiddo in the Roman province of Galilee.
The approximate location of the camp of the Legio VI Ferrata was known from the persistence of its name in the form Lajjun by which a Palestinian Arab village was known.
It was close to the ancient town of Rimmon, perhaps the Hadad-rimmon of Zechariah 12:11, which in the 3rd century was renamed Maximianopolis (City of Maximian) by Diocletian in honour of his co-emperor Maximian. Both places were within a single episcopal see, generally called Maximianopolis, but in one list of such sees the name Legionum (genitive plural of the Latin word Legio) is used, where the Greek original has "Maximianopolis".
In 2002–2003, an archaeological survey was made in the Legio region by Yotam Tepper as part of his master's thesis. The survey located the legionary camp on the northern slope of El-Manach hill, the village of Ceparcotani on the adjacent hill, and the city of Maximianopolis on the site of the contemporary Kibbutz Megiddo. In 2013 Tepper and the Jezreel Valley Regional Project dug test trenches measuring approximately 295 feet by 16.5 feet that revealed clear evidence of the camp. No military headquarters of this type for this particular period had yet been excavated in the entire Eastern Empire, and the 2013 excavations uncovered defensive earthworks, a circumvallation rampart, barracks areas and artifacts including roof tiles stamped with the name of the Sixth Legion, coins and fragments of scale armor.