Avgos grew up in a peaceful village, dreaming of living a life like the warriors he considered his heroes. At a young age, he mastered projectile weapons, specializing in the use of a bow and arrow. At some point during his youth, he left his village to join the Great Heathen Army, where he was able to rise through the ranks rapidly. Nevertheless, he remained unhappy with his position, believing he deserved more.
His career within the Great Heathen Army did not go unnoticed, and the Order of the Ancients recruited Avgos Spearhand into their ranks, promising him power and influence beyond his wildest dreams. In time, he climbed up to the position of Palatinus of the Warden of War. 
In 873, Avgos was stationed in Lunden, where he worked closely with Reeve Stowe to uphold the peace and order within the city. While Stowe considered Avgos a brother, the latter considered Reeve Stowe to be soft-handed and weak. As such, he joined The Leech and The Compass in an attack on the villa of Governor Tryggr, during which they killed him and several of his guards. During this attack, Avgos fired twelve arrows into the Governor's body, after which The Leech removed his head.
Reeves Stowe and Erke investigated the attack with the help of Eivor of the Raven Clan, who had traveled to Lunden to gain its alliance. Finding a letter from the Compass to Avgos, Eivor learned that Avgos had been tasked with recruiting archers, strengthening their hold on the city. Partaking in the archery contest, Eivor proved capable enough to meet with Avgos.
Avgos joined the recruited archers on stage to speak to the citizens of Lunden, declaring their Reeves weak and indecisive, unable to maintain order as evidenced by the brutal murder of Governer Tryggr. During this speech, Eivor eliminated Avgos, before returning to Stowe. Reeve Stowe, who had considered Avgos as a brother and a close ally, was shook by the developments, but admitted to Eivor that he had neglected to take heed of Avgos' greed and ambition.
Following Avgos' death, as well as the death of Sister Frideswid, the citizens of Lunden were enraged. They remained unaware of their allegiance to the Order of the Ancients and were under the impression that two upstanding citizens had been brutally murdered. Their deaths also served to draw The Compass, the third conspirator in Tryggr's death, back to Lunden, where he launched a full-scale attack on the city to avenge his fallen companions.
- Avgos shares many similarities with the character William of Montferrat from the 2007 video game Assassin's Creed. Both train the citizens of their cities to become militians and discipline them. They are both kill by the protagonist while making a speech to their troops.