Legio octava Augusta (Eighth Augustan Legion) was a Roman legion created by Pompey in 65 BC, along with the 6th, 7th & 9th, and continuing in service to Rome for at least 400 years thereafter.[1]
They were ordered to Cisalpine Gaul around 58 BC by Julius Caesar, and marched with him throughout the entire Gallic Wars. In 49, at the very beginning of the civil war between Caesar and Pompey, the Eighth Legion accompanied Caesar across the Rubicon into Italy. By the end, they stood against him at the Battle of Pharsalus. The legion was also present in Egypt, when Caesar captured Egypt for Cleopatra. In 46 BC the legion took part in the Battle of Thapsus (modern Tunisia), shortly before their disbandment.
In 44 BC, Augustus reconstituted the legion which had helped him attain the control of the Empire. This loyalty gave the legion the cognomen Augusta. VIII Augusta took part in the Roman invasion of Britain.
In 69 AD, the Year of the Four Emperors, following the suicide of Nero, the legion took the part of Vespasian, the new emperor. After that they took the new name, First Italic Legion. The legion also fought in Parthia with Septimius Severus (who ruled from 193 until 211) and with his successors.
Records indicate that they were still active during the first years of the 4th century at the Rhine frontier. This means that the history of the legion covers more than 400 years of almost continuous service. In 371 it was stationed in Argentoratum (Strasbourg), in Germania Superior, according to an inscription. Later, the Roman general Stilicho, was compelled to move the German legions back to Italy to defend it against the Visigothic invasion.
According to Notitia Dignitatum, around 420 an Octaviani unit was under the Magister Peditum of Italia; it is possible that this unit was the old VIII Augusta, which was originally a comitatensis unit, but that had been promoted to palatina status.