Legio VIIII Hispana

Legio IX Hispana
Map of the Roman empire in 125 AD, under emperor Hadrian, showing the IX Hispana's last attested location at Noviomagus Batavorum on the Rhine (Nijmegen, Netherlands)
Active	Before 58 BC to sometime in the 2nd century AD
Country	Roman Republic and Roman Empire
Type	Roman legion (Marian)
Role	Infantry assault
Size	c. 5,400
Garrison/HQ	Eboracum (Britannia) 71–c.121 ? Noviomagus (Germania Inferior) c. 121–130
Nickname(s)	The Lost Legion
Mascot(s)	Eagle
Engagements	Gallic Wars (58–51 BC) Cantabrian Wars (29–19 BC) Roman conquest of Britain Boudican revolt Battle of Mons Graupius
Commanders
Notable commanders	Julius Caesar Quintus Petillius Cerialis Gnaeus Julius Agricola

Legio IX Hispana ("Spanish 9th Legion"), also Legio nona Hispana ("Spanish Ninth Legion"), was a legion of the Imperial Roman army that existed from the 1st century BC until at least AD 120. The legion fought in various provinces of the late Roman Republic and early Roman Empire. It was stationed in Britain following the Roman invasion in 43 AD. The legion disappears from surviving Roman records after c. AD 120 and there is no extant account of what happened to it.

The unknown fate of the legion has been the subject of considerable research and speculation. One theory (per historian Theodor Mommsen) was that the legion was wiped out in action in northern Britain soon after 108, the date of the latest datable inscription of the Ninth found in Britain, perhaps during a rising of northern tribes against Roman rule. This view was popularised by the 1954 novel The Eagle of the Ninth in which the legion is said to have marched into Caledonia (modern day Scotland), after which it was "never heard of again".

This theory fell out of favor among some scholars as successive inscriptions of IX Hispana were found in the site of the legionary base at Nijmegen (Netherlands), suggesting the Ninth may have been based there from c. 120, later than the legion's supposed annihilation in Britain. The Nijmegen evidence has led to suggestions that IX Hispana was destroyed in later conflicts of the 2nd century. Suggestions include the Bar Kokhba revolt (132–5) or Marcus Aurelius' war against Parthia (161–6) in Armenia. However, some scholars have ascribed the Nijmegen evidence to a mere detachment of IX Hispana, not the whole legion. They continue to favor the British scenario, but concede that the legion's disaster must have happened closer to 120 than 108.

In any event, it is clear that the IX Hispana did not exist during the reign of emperor Septimius Severus (r. 193–211), as it is not included in two identical, but independent, lists of the 33 legions existing in this period.