Rome’s Lost Legion

What became of the Ninth Legion (Hispana) ?




For many years, there has been speculation about the fate of the Legio IX (Hispana), which seems to have dropped off the Roman imperial records sometime after AD 120. The most dramatic (and popular) theory is that the legion, a force that could have consisted of up to 5000 men, was marched north into Scotland and was somehow annihilated by the natives (Picts) and never seen again.

A Popular Theory Makes for Good Drama

The supposition that the Ninth was massacred to the last man, somewhere in the interior of Scotland, has the right kind of dramatic appeal to catch the popular imagination and ensure that this explanation is widely held to be true. Moreover it holds direct appeal to national pride in Britain and especially stirs nationalist sentiment in Scotland as it can be seen as a David versus Goliath scenario. Anyway, everyone likes a good mystery. The annihilation theory was the basis of Rosemary Sutcliff’s fictional book – ‘The Eagle of the Ninth‘, published in 1954, which was very well received at the time. A recent movie – ‘The Eagle’ was based on this book and another recent movie, ‘Centurion‘  also takes up the annihilation scenario. There are many, who hope that some archaeological evidence will eventually show up to prove the theory. But how realistic is it to believe that an entire legion could just disappear, without a trace?


History of the Ninth Legion in Britain

Legio IX (Hispana) had been active in Britain, from Claudius’ invasion in AD 43 onwards, but had been severely mauled during Boudica’s revolt. It was subsequently brought back to strength and archaeological evidence shows that the Ninth helped build the headquarters fortress at Eboracum (York), as evidenced by an inscription and from stamped tiles, dating to around AD 108. Therefore the legion was definitely still in Britain during Trajan’s reign (AD 98 -117). Yet, sometime in the early part of Hadrian’s administration (AD 117 – 138) the Ninth seems to have slipped out of sight and was never directly mentioned again in any extant records or inscriptions.


Irrespective of whether it remained in Britain, or was reassigned elswhere, we do have some indirect evidence that the Legio IX Hispana itself must have continued to exist as a unit – at least until around 120 AD.


We know from inscriptions that the consul for AD 143/144, Lucius Aemilius Carus had once been a military tribune with the Legio IX Hispana, as was another senator, Lucius Ligarianus, who had also become consul, prior to his appointment as governor of Cappadocia in AD 138 – 140. Both men had full senatorial careers, which included holding all the state offices required by the ‘cursus honorum’. According to this traditional career path, set out in ancient times for ambitious statesmen, they would almost certainly have been in their early forties when appointed consul and in their late teens or early twenties when they were military tribunes, serving with the Ninth. So calculating backwards, the IX Hispana must have still have been in existence as a unit, at around the time of Hadrian’s visit to Britain in AD 122, however there is no evidence that the legion was still stationed on the island at the time and had not already been posted elswhere.


A Deteriorating Situation

A less dramatic and possibly more plausible explanation, to counter the annihilation theory for the disappearance of the Ninth Legion, has been proposed.


We know from a letter from Fronto to Marcus Aurelius that there had been trouble in Britain during the early part of Hadrian’s reign and that there had been heavy casualties amongst the troops.  So it is likely that,  had it the Ninth Legion remained in Britain, throughout the unsettled period leading up to the building of Hadrian’s wall, it would probably have steadily been losing manpower by attrition and therefore would eventually have become in urgent need of new recruits and replenishment of its military resources.


If this was so, the understrength IX Hispana may well have been withdrawn from Britain, in order to restore its capacity as a fighting unit and then make it available to some other area of conflict. Assuming this theory to be true, the Ninth was very likely replaced by the Legio VI Victrix, which is known to have been transferred into Britain in AD 119, on Hadrian’s orders. The Sixth is subsequently known to have been involved in the building of the wall, but there is no evidence of the Ninth having played any part in the construction.


Hadrian’s Wall

If, on the other hand, the Ninth was not withdrawn when the Sixth arrived in 119 and still remained in Britain, helping to provide cover for the men building the wall, it is  plausible that by the time the wall had been completed (around AD 128), the Legio IX (Hispana) would have been very much under strength and no longer really viable for its primary function as an effective, self-contained tactical force, at least not without the added expense of considerable additional reinforcement.




However, as a direct consequence of the completion of the wall, the strategic situation in northern Britain by that time would have been considerably improved. Thereafter fewer troops would have been required to maintain the status quo. This was obviously the main reason behind Hadrian’s decision to build it, although it also had the secondary purpose of regulating trans-border civilian traffic


We know for sure that the wall itself was manned almost exclusively by auxiliary troops, rather than legionaries. Auxiliaries were cheaper to maintain in the field and were paid less than the legionary troops, who were all full Roman citizens. So it is therefore entirely plausible that as a matter of simple economics, the decision was made to disband an under strength legion and pay off or retire the remaining soldiers. Alternately the Ninth may simply been transferred away or have had its manpower withdrawn on a piecemeal basis, with odd cohorts or smaller tactical detachments being re-allocated separately as reinforcements to units in other parts of the empire.



 Photo by Steve Coe



 (Poster displayed at Homesteads Fort by British National Trust)


Other Possibilities

There are other possibilities – for instance, a severe plague may have wiped out numbers of troops, leaving the unit under strength and unviable. More improbably, the soldiers of the Ninth may have disgraced themselves (by cowardice or mutiny) and the legion had then been  dishonourably disbanded with its records deliberately expunged to hide the shame of the offence. (If the legion had indeed been massacred the loss could also have deliberately covered up to avoid a loss of Roman prestige and morale). There are actually many possibilities. Probably the most likely is that the unit was simply reallocated to another area of conflict and was lost to history in a later consolidation of resources, following losses in war.


Why it is Difficult to Believe that the Ninth was Massacred

A large-scale massacre always makes for exciting drama, but in fact the annihilation theory must be the least plausible solution, as the sudden loss of an entire legion – one of only twenty five such major strategic units in the entire Empire, would have been such a significant event that it could hardly have gone unnoticed by contemporary writers and escaped the historical record – even if there had been a deliberate ‘spin ‘ attempt to cover up a politically unacceptable disaster.


Moreover, if the situation in North Britain was so unstable that an entire legion could be wiped out, there would have surely been some mention of drawn-out punitive action or at least some evidence of further replacement forces being sent into the area to plug the gap in the defences left by the missing legion.  Otherwise, in this kind of crisis situation, the strategic balance of power would have tilted strongly against the Roman’s in Britain.  There is no historical or archaeological evidence for such events (the arrival of the sixth legion was too early). Therefore, one must conclude that it is  far more  likely that there was a more mundane explanation for the demise of the Ninth.


On the balance of probabilities, it seems most likely that it was only the record that was lost – not the legion!