RYSE:SON OF ROME

Ryse: Son of Rome begins with a tutorial section in the middle of the story, with Roman general Marius Titus leading the defense of Rome against oncoming CELTIC BARBARIANS led by a semi-mythical commander called "Damocles". After giving one of his soldiers a small sack and telling him to display it where the barbarians can see it, Marius helps secure the Roman emperor named Nero. in a private safe room. At the emperor's behest he begins to tell his story; the rest of the game is an extended flashback depicting Marius' adventures up to this point.

Marius begins his story off as a soldier serving in the relatively peaceful II Legion, holding a post in Alexandria, returning to his family in Rome and enjoying the adulation of his father Leontius, himself a retired legionary, now a Senator calling for reforms and the censure of Emperor Nero. Leontius, seeing potential in his son, relates the legend of "Damocles," a legendary Roman general who was abandoned to his enemies due to political expediency. With the help of Nemesis, goddess of revenge, Damocles returned from the underworld to bring vengeance to those who wronged him.

Marius' peaceful visit is cut short as a barbarian invasion takes place, resulting in the death of his parents and younger sister. In his dying words, Leontius bids Marius to slay "them". Commander Vitallion, a friend of the slain Leontius, transfers Marius to his XIV Legion, and he promises Marius vengeance for his murdered family. Vitallion leads the XIV Legion to Britain, where the fleet is ambushed off the coast; Marius leads the counter-attack, nearly single-handedly preventing the destruction of the remainder of the fleet, impressing Vitallion enough to earn a promotion to Centurion.

After reports of a rebellion at York, Marius heads North to aid the defeated legion stationed there. Upon capturing King Oswald and his daughter Boudica, Basilius, the son of the Emperor, reveals that his brother Commodus has been captured by the Barbarians whose whereabouts are unknown. Basilius, by threatening to kill Boudica, forces King Oswald into revealing the location of Commodus: he has been traded to the men north of the wall, who are fearsome in reputation. Basilius orders Vitallion and Marius to go North and bring back Commodus. After crossing the border into Caledonia (Scotland) the party is ambushed, Vitallion is taken hostage by barbarians and Marius separated from his legion. Marius makes his way into the enemy camp, where Roman legionaries are being burnt alive; he kills the barbarian leader Glott in a brutal fight and rescues Commodus and Vitallion.

Commodus returns to York with Basilius and Vitallion, where he continues to intimidate Oswald, despite Vittalion and Marius' shared observations that humiliating the foreigners will not raise Rome's standing in their eyes. Negotiations break down when Commodus murders Oswald in a fit of pique, and Marius is struck with the realization that though barbarians may have slain his father, they did so at Nero's 

instigation and with his blessing. Even worse, the Celts, led by a just-escaped Boudica, lay siege to York, with XIV Legion tasked with defending it until Commodus can escape. In the end, Marius sacrifices himself to buy time for the final ships to sail, but is resurrected by the goddess Summer, who tasks him with taking on the mantle of Damocles and avenging his family. Marius makes his way back to Rome in hopes of murdering Nero.

Marius decides to enter the gladiatorial ludi in order to confront Nero and his sons directly. Basilius has him fight several dangerous enemies in order to earn his entrance. Marius emerges victorious and is able to slay Basilius during a private audience. After fighting his way through the Colosseum, Marius confronts Commodus, emerging victorious after a grueling set of battles involving several body doubles, anachronistic poison gas and the overconfident Commodus boasting to the crowds that he is immortal even as Marius manages to draw blood for the first time. As "Damocles" and Nero jointly call for each other's deaths, Marius escapes, meeting up with Vitallion, now the head general of Rome's garrison. According to Vittalion, Boudica is due in only days, having gathered enough barbarian support to storm the capitol itself. Vitallion agrees to help Marius put an end to Nero's rule, but his first priority is saving Rome. Their efforts are largely successful, but Vitallion is slain in a one-on-one duel with Boudica. Marius takes up the command as well as the duel and defeats her in turn, though his victory is tempered by their shared realization that they are both victims in Nero's power plays.

This brings Marius to the "present day" of the game's narrative: he gives the small sack, containing Boudica's head, to his subordinate, and escorts Nero to his safe room. Nero, who has long since deduced that Marius is Damocles, flees deeper into his bolt hole. As Marius gives chase, he is temporarily distracted by Aquilo, the god of the north wind, who has been aiding Nero this entire time and whose stated goal is to cause the collapse of Rome; his intervention allows Nero to deliver Marius a mortal wound. However, Summer helps Marius claim the victory, tossing both Nero and himself off a parapet to their mutual deaths.

The story ends with the barbarians retreating from Rome, and their leader fled after that war

you can read more story in www.wikipedia.org