The Lost Legion: The Legio IX Hispana

Podcast Transcript

One of the most legendary legions in the history of the Roman military was the Legio IX Hispana, or the Ninth Spanish Legion.

They served under Pompey the Great and later with Julius Caesar in Gaul. They later served Augustus and were pivotal in the conquest of Britain under Emperor Claudius.

Then at some point, they simply disappeared. There was never a mention of them again in the historical record.

For almost 2000 years, it has been one of the world’s greatest historical mysteries.

Learn more about the missing Legion and what might have happened to them on this episode of Everything Everywhere Daily.

In a previous episode, I covered how Roman armies worked. The base unit of the Roman military was the legion.

A Roman legion typically consisted of about 5,000 to 6,000 soldiers. The number could vary based on the legion, circumstances, and period in history, but 5,000 to 6,000 was the historical average.

In addition to the core infantry forces, a legion also included support personnel such as engineers, clerks, medics, blacksmiths, and animal handlers, as well as a small cavalry unit. When auxiliaries, who were non-citizen troops attached to legions, are included, the total fighting force associated with a legion could exceed 10,000 men.

On top of that, estimates suggest that for every legionary soldier, there might have been at least one and possibly as many as two civilians. The civilian may have included legionaries’ unofficial wives or concubines, children, merchants, prostitutes, and slaves.

Legions were initially raised from Roman citizens during the republican period and later became professional armies.

Throughout history, legions would be raised and occasionally disbanded. Three legions were disbanded for cowardice after the Batavi revolt in the year 70.

The 17th, 18th, and 19th legions were wiped out in the Battle of Tuteberg Forest, and those names were never used again.

Most legions existed for decades, if not centuries. Over time, they developed distinct identities that went beyond their function as mere military units, evolving into institutions with deep cultural significance, proud traditions, and fiercely guarded reputations.

Each legion developed its personality through the accumulation of battle honors, the cultivation of specific traditions, and the development of distinctive customs that set it apart from other units.

This process began from the moment of formation and continued throughout the legion’s existence, creating military cultures that could persist for centuries.

All legions were given a number. The highest numbered legion that we know of was the 30th. They also had a moniker, which came from some early battlefield accomplishments.

The Tenth Legion was known as Fretensis, which means “of the straight,” and is based on their naval accomplishments.

The Twelfth Legion was known as Fulminata, which means thunderbolt.

Most legions had a name based on a geographic area where they found game, including Germany, Syria, Macedonia, Gaul, and Sicily.

And of course, each Legion had a standard which was considered to be an almost sacred object. A standard, which was a golden eagle, was carried into battle, and the most humiliating thing that could happen to a legion was the loss of its standard.

Emperors sometimes negotiated for decades to get lost standards returned.

The point of all of this is that legions were large and important things that had a continuity that lasted for centuries. Legions didn’t just disappear.

That brings me to the subject of this episode, the Legio IX (nonam) Hispana, or the 9th Spanish Legion.

Its origins trace back to the late Roman Republic, most likely around the year 65 BC, during the campaigns of Pompey the Great in Hispania, which is the source of its honorary title Hispana.

By the time of Julius Caesar’s Gallic Wars, the Ninth Legion was a seasoned and respected force. It played a prominent role in Caesar’s conquest of Gaul and later supported him in the civil war against Pompey, fighting at key battles such as Pharsalus in 48 BC.

Following Caesar’s assassination, the legion served under his heir, Augustus, during the final conflicts of the Republic. After Augustus secured his power, the legion was stationed in Hispania for some time and subsequently deployed to the Rhine frontier.

Under Augustus and his successors, the Ninth Legion participated in numerous campaigns that expanded and consolidated Roman power. The legion fought in the Pannonian revolts in the Balkans.

The legion’s most famous chapter began with the Roman invasion of Britain in 43 under Emperor Claudius. The Ninth Legion formed part of the invasion force that established Roman rule in southern Britain, and it would remain associated with the British frontier for the next several decades.

This posting was both prestigious and dangerous, as the legion found itself at the forefront of Rome’s expansion into one of Europe’s most challenging regions. During the early years of the conquest, the Ninth Legion established itself in the modern city of Lincoln, known to the Romans as Lindum Colonia.

This location was strategically chosen to control the gap between the Pennine Mountains and the North Sea, effectively dividing the unconquered tribes of the north from those already under Roman control.

The legion’s most severe test came during Boudica’s rebellion in the years 60 and 61, one of the most serious challenges to Roman rule in Britain, which I covered in a previous episode.

When Queen Boudica led her confederation of tribes in revolt, the Ninth Legion marched south from Lincoln to help suppress the uprising. However, the legion walked into a carefully prepared ambush and suffered catastrophic losses. Classical sources suggest that the legion lost most of its infantry, with only the cavalry and senior officers managing to escape back to their fortified camp.

This disaster might have ended the story of most Legions, but the Roman system was remarkably resilient. The Ninth Legion was rebuilt with fresh recruits and reinforcements, showing the empire’s ability to recover from even severe setbacks.

Following its reconstruction, the Ninth Legion continued to serve on the British frontier, participating in the campaigns of Gnaeus Julius Agricola in the 70s and 80s. These campaigns pushed Roman control far into Scotland, and the legion likely fought at the famous battle of Mons Graupius, where Agricola claimed to have decisively defeated the Caledonian tribes.

Archaeological evidence suggests the legion maintained bases in northern England and southern Scotland during this period.

The mystery of the Ninth Legion begins in the early second century. The last definitive evidence for the legion’s presence in Britain comes from inscriptions and archaeological finds dated to around the year 108. This last inscription can be seen at the Yorkshire Museum in York, England.

After this point, the historical record becomes silent. No further inscriptions mention the legion, no military documents reference its activities, and archaeological evidence for its continued existence simply vanishes.

I should reiterate that many of the legions from this period existed well into the 4th or 5th centuries.

If a legion was disbanded, it probably would have been due to some disastrous defeat, and there is no such defeat in the historical record.

So, what happened?

Well, we don’t know. There is no definitive evidence pointing to anything. All we have are theories.

The theory which dominated the 19th and early 20th century was developed by the German historian and winner of the 1902 Nobel Prize in Literature, Theodor Mommsen.

Mommsen’s magnum opus, and the work for which he was awarded the Nobel Prize, was A History of Rome.

Mommsen believed that Legio IX Hispana met its end in Britain, most likely during a major but poorly documented military disaster in the early 2nd century. He placed this event sometime during or shortly after the reign of Emperor Trajan, when evidence of the legion abruptly vanishes.

Mommsen hypothesized that the Ninth was destroyed in the far north of Britain, possibly in modern-day Scotland, during an expedition against the Caledonian tribes. This theory was rooted in the assumption that the lack of later inscriptions in Britain indicated its annihilation.

In his analysis, Mommsen emphasized the pattern of Roman military administration and frontier policy. He believed that a major loss like the destruction of the Ninth would explain the decision to withdraw from further northern expansion and ultimately to build Hadrian’s Wall in the 120s, under Emperor Hadrian.

Absent any other evidence, Mommsen’s hypothesis was widely accepted for decades. To be fair, it wasn’t a crazy idea. It explained why the Romans pulled out of Scotland, and it also ties cleanly to the last known location of the legion.

Mommsen’s theory was the basis for several fictional works, including Rosemary Sutcliff’s 1945 novel The Eagle of the Ninth and the 2007 movie The Last Legion.

However, in the 1990s, a significant archaeological discovery in Nijmegen, Netherlands, contributed to a major shift in scholarly thinking about the fate of Legio IX Hispana.

This discovery included a cache of Roman military artifacts, notably tiles, inscriptions, and coins, which provided fresh evidence that elements of the Ninth Legion were present on the continent, specifically in the Rhine frontier region, after its last known activity in Britain.

The Nijmegen findings built upon earlier discoveries from the 1960s and 1970s, including a tombstone of a centurion of the Ninth, but the 1990s excavations reinforced the argument that the legion, or at least a significant detachment of it, had been transferred from Britain to the Rhineland around the early 2nd century.

Among the more consequential finds were roof tiles stamped with the mark of the IX Hispana, and coins dating from the reigns of Trajan and Hadrian, strongly suggesting that these tiles and the structures they were part of were constructed in the early to mid-2nd century.

This contradicted the long-standing theory popularized by Mommsen and others that the legion was destroyed in Britain.

Instead, the Nijmegen evidence suggested that the legion survived the Boudican revolt and continued to operate after the year 108, the date of its last known inscription in York.

However, while this evidence indicates a presence of the Ninth in Nijmegen, it does not conclusively prove the entire legion was stationed there, nor does it conclude what ultimately happened to it.

As a result, since the 1990s, the academic consensus has shifted away from a purely British-based destruction of the Ninth. Instead, scholars now consider it more likely that the legion was transferred out of Britain sometime after 108 and ultimately vanished from history under uncertain circumstances sometime in the 2nd century.

The Nijmegen artifacts change the story of the “Lost Legion,” but it doesn’t fundamentally solve the mystery.

We still have no idea what happened to the legion. We can be reasonably sure that they weren’t destroyed or disbanded in Britain, but that just moves the mystery forward a few decades.

New theories have come forward, which include the legion being sent to Judea, Armenia, the Balkans, or just being merged into other legions.

Unless new archeological discoveries are made, we may never know what happened to Legio Nonam Hispanica.

No matter how many theories about them are put forward, they might forever be the Lost Legion.