In the year AD 140, twenty years after the Ninth Legion disappeared in the north of Britain, Marcus Flavius Aquila, a young Roman centurion, arrives in Roman Britain to serve at his first post as a garrison commander. Marcus's father disappeared with the eagle standard of the ill-fated legion, and Marcus hopes to redeem his family's honour by bravely serving in Britain. Shortly afterwards, only Marcus's alertness and decisiveness save the garrison from being overrun by Celtic tribesmen. He is decorated for his bravery but honourably discharged due to a severe leg injury.
Living at his uncle's estate near Calleva (modern Silchester) in southern Britain, Marcus has to cope with his military career having been cut short and his father's name still being held in disrepute. Hearing rumours that the eagle standard has been seen in the north of Britain, Aquila decides to recover it. Despite the warnings of his uncle and his fellow Romans, who believe that no Roman can survive north of Hadrian's Wall, he travels north into the territory of the Picts, accompanied only by his slave, Esca. The son of a deceased chieftain of the Brigantes, Esca detests Rome and what it stands for, but considers himself bound to Marcus, who saved his life during an amphitheatre show.
After several weeks of travelling through the northern wilderness, Esca and Marcus encounter Guern, a Roman born Lucius Caius Metellus, one of the survivors of the Ninth Legion, who attributes his survival to the hospitality of the Selgovae tribe. Guern recalls that all but a small number of deserters were killed in an ambush by the northern tribes â including Esca's Brigantes â and that the eagle standard was taken away by the Seal People, the most vicious of the tribes. The two travel further north until they are found by the Seal People. Identifying himself as a chieftain's son fleeing Roman rule and claiming Marcus as his slave, Esca is welcomed by the tribe. After allowing the Seal People to mistreat Marcus, Esca eventually reveals that his actions were a ploy and helps his master to find the eagle. As they retrieve it, they are ambushed by several warriors, including the Seal Prince's father. Marcus and Esca manage to kill them and, with the aid of the Seal Prince's young son, escape from the village.
The two flee south in an effort to reach Hadrian's Wall, with the Seal People in pursuit. Marcus, slowed by his old battle wound, orders Esca to take the eagle back to Roman territory and even grants the reluctant slave his freedom. Freed, Esca still refuses to abandon his friend and instead heads out to look for help. He returns with the survivors of the Ninth Legion just as the Seal People catch up with them. The legionaries, wishing to redeem themselves, accept Aquila as their commander and prepare to defend the eagle standard. As an example to those who would betray their people, the Seal Prince kills his young son in front of Esca, Marcus, and the legionaries. He then orders his warriors to attack. A battle ensues, in which the Seal Prince and all his warriors are killed, along with most of the Ninth Legion soldiers. With the enemy defeated, the bodies of both Britons and Romans are laid out by the victors. As Marcus commends their valour, he lights a funeral pyre for Guern. As Guern is cremated, Marcus, Esca and the few survivors of the Ninth return to Roman territory, where Aquila delivers the eagle to the astonished governor in Londinium. There is some talk of the Ninth Legion being reformed with Marcus as its commander. But when Marcus and Esca wonder what they will do next, Marcus leaves the decision to Esca.
Alternative ending[edit]
An alternative ending is featured in the DVD. Marcus decides to burn the eagle standard on the altar where the final battle occurred, instead of delivering it to the Roman governor. He tells Esca that he does this because the eagle belongs to the men who fought for it. Marcus and Esca are then shown approaching Hadrian's Wall on foot and talking about their plans for the future.
Who do the legionaries accept as their commander?
Aquila