The mysterious disappearance of Rome's Ninth Legion

The Roman legions are famous for their ruthless discipline and relentless wars of expansion. One of these legions has become famous both for its success on the battlefield and for the mystery surrounding its disappearance. This was the Ninth Legion. It was one of the most famous of all the Roman legions since they fought with distinction for both Julius Caesar and the Emperor Augustus. However, by the end of the second century A.D., this elite force of several thousand soldiers had disappeared without a trace. Where did they go, and what happened to them? To begin answering these questions, let's start with what we know. The Ninth Legion was formed sometime in the first century B.C. and served in both Caesar's Gallic Wars and Augustus' civil war against Marc Antony. Then, in A.D. 43, it participated in Emperor Claudius' invasion of Britain. They fought during Boudicca's infamous revolt in A.D. 51, before being sent north to conquer central Britain in the 70s A.D. There, they constructed a military camp complex known as Iberacum, which became the modern-day city of York. This is where the mystery begins. According to inscriptions discovered in York, the Ninth Legion remained at Iberacum until at least A.D. 108. However, all traces of the Ninth Legion in Britain completely vanish after this point. By A.D. 122, a different legion, known as the Sixth Victrix, had replaced the Ninth at Iberacum. But there is one more tantalizing clue. There is one last mention of the Ninth Legion after A.D. 122, but it is not from Britain. Two short inscriptions naming troops from the Ninth Legion were found in the Netherlands. These have been dated around A.D. 120. Is this where the Ninth went? Academics are cautious, as they note that these inscriptions only reference one detachment of the Ninth, not the whole legion. And that is all we know. The next time we get any useful information is from A.D. 197, almost 80 years later. These are, in fact, two separate records, both listing all of the active legions of Rome at the time. Curiously, both lists give exactly the same names of 33 legions operating in A.D. 197, but the Ninth does not appear on either one. It was gone. So, sometime between A.D. 122 and 197, an entire Roman legion utterly vanished. But why? Since we have no other information, historians have been scrambling to work out the most likely cause. The complete disappearance of an entire Roman legion is incredibly rare. Therefore, something dramatic must have occurred. Here are four of the most likely explanations offered by scholars. The most famous theory is that the Ninth Legion must have been annihilated in an unknown battle in Britain. It is believed that only a disaster like an ambush by local tribes would be the best explanation for their disappearance. However, since some of the legion is mentioned to be in the Netherlands, this theory has fallen out of favor recently. The second option proposes that the Ninth Legion was redeployed from Britain to help suppress the Second Jewish Revolt in A.D. 132. This time frame would fit with the current evidence, and they could have been destroyed during this conflict. However, there is no evidence that the Ninth Legion was present in the Middle East at this time. A third theory is that they were destroyed during the Parthian War in the 160s. Interestingly, Roman historian Cassius Dio says that an unnamed legion was destroyed during this conflict. It might have been the Ninth, but again there is no record of them being in this part of the empire. The fourth and final option is that the Ninth Legion was simply decommissioned, and its troops redeployed to other legions throughout the Roman Empire. However, it is very unlikely that such a famous legion like the Ninth would be simply disbanded. So despite these theories, the enigma of the Ninth Legion's disappearance remains unsolved. The sheer lack of information means that their disappearance may remain a mystery forever. If you enjoy learning about ancient Roman history, be sure to check out our video on the Vestal Virgins. I look forward to seeing you again in our next video.