The ninth legion was present during the whole campaign of the Gallic wars. Later, they remained faithful to Caesar in the civil war against the conservative faction of the senate led by Pompey. They fought in the battles of Dyrrhachium and Pharsalus (48 BC) and in the African campaign of 46 BC. After his final victory, Caesar disbanded the legion and settled the veterans in the area of Picenum.
Following Caesar's assassination, Octavian recalled the veterans of the ninth to fight against the rebellion of Sextus Pompeius in Sicily. After his defeat, they were sent to the province of Macedonia. The ninth remained with Octavian in his war of 31 BC against Marcus Antonius and fought by his side in the battle of Actium. With Octavian as sole ruler of the Roman world, the legion was sent to Hispania to take part of the large scale campaign against the Cantabrians (25-13 BC). Their surname Hispana likely dates from this events as and was probably earned for distinction in fighting.
After this, the legion was probably a member of the imperial army in the Rhine border that was campaigning against the Germanic tribes. Following the abandonment of the Eastern Rhine area (after the disaster of the battle of the Teutoburg Forest – 9AD), the ninth was relocated in Pannonia. In 43 AD they participated in the Roman invasion of Britain led by emperor [Claudius. The ninth suffered important losses in the rebellion of Boudicca (60 AD) and was later reinforced with legionaries from the Germania provinces. Their last record in Britain dates from the early 2nd century, when the legion built a fortress near York. Then, apparently they were moved to Germania Inferior.
From about 120 AD on, the legion disappears from the records. It was destroyed in the reign of Marcus Aurelius, either during the Judea rebellions of Simon bar Kokhba (130s) or in the Danube revolts (160s).
See also: List of Roman legions