Artorius is an Imperial born in 4E 171 in Riverwood, Skyrim. He is an adventurer who leads a band of knights out of a hall built near Helgen.
Artorius' father was a well respected Legate in the Legion, serving in Skyrim. At the surprise of everyone near him, his father married a poor Nord woman named Freyja from Riverwood, where they chose to live and raise Artorius and his sister, Morwen. One day an Imperial messenger came with grave news, Artorius' father had been kiled in combat. His father's sword, Veydwiin, was placed in his father's burial mound outside Riverwood. On the 11th of Frostfall, when Artorius had seen twelve winters, Riverwood was attacked by a large group of Nord bandits. In the battle, they set houses on fire and Artorius' mother was trapped inside. He ran to his father's grave and pulled on Veydwiin, saying, "Father, let loose your sword". It came loose, and he took it back to the house, but beheld an inferno, nothing left, his mother screaming no more. He fell on his knees and wept, holding Veydwiin. After this incident, he was cared for by one of his father's friends, a retired Nord Imperial Battlemage and Warrior, Nilruhm. This man trained him from that moment on, seeing the boy's potential. After turning 18, he joined the Legion and worked to serve the Empire like his father before him.
He served faithfully in the Legion, believing it was what his father would want him to do. Artorius rose quickly in rank and was made a captain fighting the Stormcloaks. His new charge was with nine soldiers, called Lancelin, Gerdos, Artorius' nephews Bormir, Borandr, and Borgar, Bedivere, Kai, Tristan, and Percivel. They were a very loyal and successful group, renowned across the land for their skills. People spoke of their courage, honor, chivalry, and nobleness.
On 6th of Last Seed of 192, Artorius and his squad were tasked with clearing a fort of bandits. Everything seemed normal, but when they got to the fort, they found it empty. The fires inside the fort were still lit, so they cautiously entered the building. They split up and searched for anything suspicious, with nothing to be found. When went back outside, they were surrounded by Stormcloaks. Artorius was about to order the attack, when out of the Stormcloak ranks approached Nilruhm. Artorius was outraged, calling him a two-faced traitor. He simply could not believe his foster-father could be a Stormcloak who passed false information.
Nilruhm explained to Artorius that he had been training him to eventually switch sides. He told Artorius: "This land is your home. That sword you carry, twas made of steel from this earth, forged in the fires of Skyrim. Ours is your cause, we are your people."
"Was it my people who raided my village? Who burnt everything?" He told the story of his mother's death, and how he eventually found out that it had been Stormcloaks trying to rid the town of Imperial influence.
Artoruis responded: "How dare you. You Stormcloaks needlessly meddle and kill. I can feel the heat of that fire on my face even now."
"How many Stormcloaks have you killed?" Nilruhm said.
"As many as have tried to kill me. It is the natural state of any person to want to live." Artorius said.
A Stormcloak woman with a bow strapped to her back stepped forward and said: "It is the natural state of any person to want to live free."
Nilruhm said, "Guinveir, stand down. Artorius, your mother and father were both supporters of our cause before you were even born. Your sister is with us, and her husband is one of us."
"It's true," Bormir said to Artorius, "Our father Bormir has always been a Stormcloak. My brothers and I planned to join after serving with you. But now, we will follow your lead Artorius."
"Aye, us too." said Kai, with nods from all except Lancelin.
Artorius was being swayed, but he needed his greatest friend's input. "Lancelin?"
Lancelin had a stern look on his face. "This isn't my fight. Not yours either Artorius."
Artorius said, "You would say that, you, who know me best of all."