[Yes, this is me being silly in a very verbose way.]
The 9th Legion has long been a source of considerable mystery because it disappears from the historical record without note. Certainly other legions were disbanded, two 12th legions were disbanded for example, but not without any clue as to what happened. It last appears in the historical record in 108 AD, at which time it is stationed in York.
It's not until decades later that the 9th becomes conspicuous via its absence. Many theories have been provided, but nothing really tells us the story. Fortunately we have an answer to this problem: movies.
Movies are a source of troves of information but suffer from the same problem as all "texts", that being one of transmission. When we have multiple sources we can at least see where they diverge and thus have some reasonable basis for deciding what to believe and what to disbelieve. When we have only one source it's much more difficult, and it involves a lot more guesswork, to put together a theory of what to believe.
Scholars pour over the dialogs of Plato trying to separate the real Socrates from Socrates as used by Plato as his mouthpiece. A similar approach is taken when examining the film Serenity as we try to sort out what is truly Firefly and what is addition, condensation, commentary, opinion, corruption, omission, authorial bias, polemic, didactic, and so forth. Is, "Guy killed me, Mal. He killed me with a sword. How weird is that?" Firefly? Is the black man dying first?
In other words, while films may inform us of the fate of the 9th Legion they cannot be taken at face value, we have to recognize that no historical document ever reaches us in a form truly representative of what happened. At the same time we try to recognize, control, and account for our own biases and filters we must also be attempting to sort through the biases and filters in the work we are viewing.
Three films inform of us of the fate of the 9th Legion.
Centurion (2010) - Shows the fall of the 9th, what happened to the non-deserters, the alleged suppression of the legions fate, and the building of Hadrian's Wall.
The Eagle (2011) - Shows the actions that would lead to the reinstating of the 9th, attitudes toward it's disappearance, and what happened to deserters.
The Last Legion (2007) - Shows the final fate of the 9th at the fall of the Roman Empire.
Some parts were clearly edited for genre, style, or just so that big names could be thrown around. This is most clear in the first story in this odd trilogy, so we may fruitfully begin there and allow Centurion to demonstrate the transmission problems we encounter in cobbling together the story of the 9th.
Centurion is a condemnation of Rome and essentially indicates that the only way to win is to turn one's back on Rome. For those who don't the unwinnable game plays out as a story of failure, death, and gore.
The title character is Quintus Dias, a centurion at of a a frontier outpost. The story begins when his outpost is destroyed by Picts. He is spared the fate of his men because the fact he knows their language is thought to be of some value.
Before the 9th even appears in the story we see some editing and streamlining to simplify the story. The natives are shown to be united into a single kingdom (Picts) under the rule of one man. Tribes banding together to fight against Roman Britannia is completely believable, it happened multiple times before (see Boudica, for example) but tribes uniting into one is simply inaccurate. The presentation of Picts to the north and Romans to the south is a gross oversimplification of the political climate of the time.
Also we see the use of famous names to give grandeur to the story. The outpost we see destroyed is supposedly Inchtuthil. Inchtuthil was no small outpost. It was the headquarters of an entire legion. It was not destroyed in war but instead methodically dismantled. The nails that had been used to hold it together were buried, likely to keep the natives from using them. Finally, it was abandoned some 20 to 30 years before the movie takes place.
The story then moves to the 9th. Against the general's reservations the 9th is ordered north to eliminate the leader of the Picts. Since there was no leader of the Picts more likely scenario would be that Rome was seeing tribes band together again and wished to eliminate the leader of the confederation, but the tribes were still distinct.
The governor is said to be Gnaeus Julius Agricola, but it is also clearly indicated and stated outright that the Emperor at the time is Hadrian.
Depicting the governor of Britannia as Agricola is entirely out of place historically, but makes sense when one realizes what the author is attempting. Agricola's son in law Tacitus wrote a biography of him at the beginning of the Nervan dynasty, apparently in an attempt to influence the new emperors by providing them with an example of good leadership.
Tacitus' biography of Agricola became famous and survives to this day. The founders of the United States looked to it for guidance.
Agricola is thus the most famous and most respected Roman governor of Britannia. To invoke his name instead of Quintus Pompeius Falco* (the likely governor given the timing of events) gives the work a grander feel, and to tear him down in the work is to tear down the Roman idea of good governance.
In fact Agricola was ordered to return to Rome by the emperor Domitian in 85 AD, some believe that it was because he was out-showing the emperor. Hadrian was less than ten years old at the time. After Domitian was assassinated the reign of the "five good emperors" began. Nerva replaced Domitian, but soon died of natural causes. His (adult) adopted son Trajan replaced him. Trajan adopted Hadrian and it was only upon Trajan's death, again by natural causes, that Hadrian ascended to the throne.
In other words: serious transmission issues here.
The author's desired story and moral conflict with accuracy and accuracy is tossed aside.
What is significant is that the 9th's general points out that they've never had any luck in finding the native leader and the governor responds by giving him the best available guide, a mute native woman named Etain.
Etain leads the 9th north. They encounter the titular centurion and save him from being executed on the spot at the end of a failed escape attempt.
Not long after the 9th is led into an ambush by Etain. The order to retreat never reaches the rear of the Roman line, so those ahead cannot fall back. Surrounded and occupying the low ground. The legion falls.
Between the initial battle and the end of mopping up operations Quintus, five soldiers, and a cook awaken on the battlefield. When one reveals that the general had been captured rather than killed the seven men attempt to mount a rescue mission.
They witness other Roman survivors from the battle being hunted down and killed by native warriors led by Etain.
They ultimately fail to save the general, who instead orders them to fall back and orders Quintus to save the remaining six men by leading them back to Rome safely. The remainder of the movie largely centers around Quintus failing to do just that.
Before it gets that far, though, two things happen. One is that one of the soldiers, Thax, kills the Pict king's son thus earning an order that the Romans be hunted down and killed. The other Romans are unaware of this at the time.
The other is the narrative tripping over itself to condemn Rome with the revelation of Etain's back story. Her story, which explains why she hates Rome, is quite horrific. Unfortunately for the attempt to damn Rome with that horrific story, it also makes little sense. She was the only witness to the events described, but she herself was unable to describe them. Where, then, does the story come from?
This could easily be solved if Etain were able to write or communicate some other way, but all evidence is that those who wished to silence her did so effectively.
Regardless, Etain kills the general. She also throws the legion's standard, an eagle made of gold, into a fire. (The fire in question would not be hot enough to melt the gold so this must be seen as a symbolic act.) Then the Pict king sends her to hunt down and kill the remaining romans.
At this point the film becomes the story of how those Romans were killed off one by one. When the first dies the same confrontation separates them into two groups each of which think the other is dead. Thax disables his companion and leaves him to die in order to escape wolves pursing them both.
The other four are reduced to three before they run across Arianne, a Pict who was exiled after being accused of witchcraft.
A short exchange again shows how style is elevated above accuracy. Quintus says, "We were 3,000, now we are 3." Those numbers go together nicely, but the primary soldiers alone would have numbered above 5,000 and if the general tapped the auxiliaries the number would have been above 11,000. This doesn't include non-military staff traveling with them, as evidenced by the non-combatant cook.
Regardless, Arianne shelters them and points them to a Roman outpost.
Arriving at the outpost they find it abandoned and learn that the emperor Hadrian has given orders to fall back. This is semi accurate. Hadrian's reign was one of consolidation which did include falling back from unconquered areas. However, as with the abandonment of Inchtuthil, the Roman army wouldn't likely have left an outpost intact for the enemy to take over.
Making their stand at the abandoned outpost, the three are able to defeat the force chasing them, but are reduced to two in the process.
The two reunite with Thax before reaching the new frontier, where they see Hadrian's Wall beginning to be built. While the other soldier, oblivious, rides toward Roman territory, Quintus and Thax get into a confrontation over the fate of the Pict king's son. Quintus blames the deaths that have occurred since the failed rescue attempt on the murder, and thus blames them on the murderer: Thax. Thax attempts to kill Quintus but dies in the process. The time this takes puts Quintus too far behind the last remaining soldier to make him to stop. Mistaken for a Pict, the last loyal soldier of the 9th is killed by Roman boarder guards.
Quintus is greeted as a hero for returning with the news, but it is decided that it is best for the fate of the 9th to remain a mystery for public relations reasons. The exact quote is, "If word gets out every tribe in every nation will rise against us." This also seems dubious. The first emperor, Augustus, saw three of his legions destroyed by Germanic tribes. When he learned of this his response was not to suppress the story but instead, as reported by Suetonius, to repeatedly bang his head into a wall while saying he wanted his legions back.
(Also the numbers of those legions (the 27th, 28th, and 29th) were never used again.)
Regardless, an attempt is made on Quintus' life and he flees Rome to live in exile with Arianne.
The second movie, The Eagle, is a story of family honor, redemption, friendship, and such things. It takes place 20 years after the fall of the legion, at which point only deserters remain alive. Its attitude toward the Roman Empire is largely neutral. It exposes many of the horrific flaws of Rome, but does not editorialize on them.
In some ways it is more damning to Rome than Centurion because its even handed presentation of Roman imperialism is no more flattering than Centurion's clearly biased presentation.
While the 9th disappeared without a trace it is common knowledge amoung the Romans that legions don't disappear without reason and thus assumed that it had been slaughtered. In some ways more damning than the loss of the legion was the loss of its eagle.
When three legions were lost to Germanic tribes the territory lost in that war was abandoned and no attempt was ever made to recapture it but decades were spent in (eventually successful) attempts to recapture the three lost eagles.
The story follows Marcus Flavius Aquila, the son of the 9th's general, as he tries to redeem his family name. Initially he is given a minor military posting in Britannia. He is soon injured in combat and he is commended and decorated for his honor but discharged due to the injury.
Marcus recovers from his injuries at his uncle's estate in southern Britannia. While there he is instrumental in getting a slave spared in the arena. In response his uncle buys him the slave, Esca.
When rumors of the lost eagle being sighted are reported from Hadrian's Wall, a recovered Marcus, accompanied by Esca, journeys north of the wall to retrieve it.
(Everything that happens north of the wall is basically impossible to gauge the accuracy of, owing to a lack of records.)
Esca hates Rome, but considers himself in debt to Marcus and so does not attempt to flee or betray him.
Eventually the two reach the site of the battle where a deserter who was taken in by hospitable locals recounts the battle. Esca could have done the same as his father, a Brigantes chieftain, fought in it. A coalition of tribes, it is said, banded together to ambush the Romans.
The Eagle was taken by the most ruthless tribe: the seal people
Marcus and Esca journey to the seal people's territory where he claims that Marcus is his slave and uses his lineage to be invited into their camp. He and Marcus steal back the Eagle, are caught in the act, kill the ones they are caught by, and then escape. Their escape is witnessed by a child from the group but, since he does not know it is an escape, he is convinced to be quiet about it.
Warriors from the seal people pursue; Marcus is slowed by his injury. Marcus grants Esca his freedom and forgives him of any debt and asks him to flee, but instead Esca recruits deserters from the 9th who come to the aid of Marcus in hopes of redeeming themselves.
Before the battle the young seal person who failed to announce their departure is executed as an example of what happens to "traitors".
In the battle the pursuing warriors of the seal people and most of the deserters from the 9th Legion are killed. Marcus, Esca, and the survivors make their way to Hadrian's Wall.
When Marcus returns the Eagle there is talk of reinstating the ninth with him in charge but instead he walks out on the higher up Romans and has Esca decide what they will do next.
We don't have stories for what happened between the 9th's reinstatement and the fall of Rome. Instead our next and last chapter is as the Western Roman Empire is falling. It takes place some three hundred years after The Eagle, and only hints at what may have happened during those years.
And this is the point where my computer crashed. Twice.
So I'm just going to post as is and come back to The Last Legion later.
* His full name was Quintus Roscius Coelius Murena Silius Decianus Vibullius Pius Iulius Eurycles Herculanus Pompeius Falco