Shef was born in a noble household, son of the thane's wife and a Viking raider. He was raised in the thane's household alongside his stepfather Wulfgar's legitimate son Alfgar and Godive, Wulfgar's daughter by a concubine. Shef is treated like a slave, and lacks only the iron collar about his neck to make it official. Despite this, he is technically a freeman and has a sword that he made himself, hiding in the forge from his stepfather's rages. Thus he is with the thane's levy when the great Viking Ragnar Lothbrok is captured, and witnesses his execution in the Snake Pit of king Ella of Northumbria.
When the four Ragnarssons hear of their father's death, they come for vengeance with their mighty army flying the Raven Banner. One of the outriders is Sigvarth Jarl, who raided Shef's home once before and left his mother pregnant. This time he crowns his atrocities by maiming thane Wulfgar and taking Shef's childhood sweetheart as a slave to give to the dreaded Ivar the Boneless. Shef schemes his way into the Viking camp to rescue her, and finds himself caught up in the fates of kingdoms and armies.
An ill-fated rescue attempt leaves Godive in a worse slavery yet, married against her will to her brother Alfgar, while Shef has an eye put out for his betrayal of the army. By his actions, he splits the army, with the followers of the Way, a new version of the Norse faith built as a direct rival to Christianity, following Shef, while the pirates and berserkers who value blood and force above all else stay beneath the banner of the Ragnarssons.
Contains examples of:
- Allohistorical Allusion: There are many of them, both subtle and large, from the English shouldering 'bows and bills' to the King of all England questing for the Holy Grail, to the French fighting the Vikings at Hastings (about 200 years earlier, though).
- All Trolls Are Different: In One King's Way a troll or "marbendill" is a large intelligent humanoid that sometimes feeds on human flesh, lurks in the water to pull unwary boaters under, but otherwise is rather likable, actually. Distinguished from humans by, among other things, a much lower sex drive; human behavior in that regard rather amuses them.
- Alternate History: The protagonist helps start a more organized and benevolent form of the Norse religion which comes into conflict both with the more traditional Norse religion and Christianity.
- Asskicking Equals Authority: Truth in Television to a great extent. The Ragnarssons and their father are all famous champions with a history of victorious battles behind them, and this fame allows them to attract followers. In One King's Way, Shef duels the King of Sweden to the death for the right to the throne.
- Badass Boast: Ragnar Lothbrok replies to an offer of mercy if he turns Christian and repents his Viking ways to live as a slave. Doubles as Defiant to the End:I fought in the front for thirty winters, Always I struck with the sword.Four hundred men I killed, a thousand women I ravished, many minsters I burned, many men's bairns I sold.Many have wept for me, I never wept for them. Now I come to the orm-garth, like Gunnar the god-born.Do your worst, let the shining worm sting me to the heart. I shall not ask for mercy.Always I struck with the sword!
- The Berserker: The series features a realistic Nordic berserkr (although he's actually Saxon by birth) as a major supporting character. When not fighting, he's brooding and melancholy, prone to fits of heavy drinking. When fighting, he's a Death Seeker. One of the main characters notes that all "true" berserkrs are inherently Death Seekers.
- Corrupt Church: The Christian Church is consistently shown as a corrupt institution, hoarding silver to itself and disturbing a functional peace in favor of crusades for more power.
- Deliberate Values Dissonance: The trilogy is set in 9th century Europe, and the values of the historical peoples of the time are accurately represented; including their attitude toward rape, enslavement, trial-by-combat, and the social status of women and conquered peoples.
- Eye Scream: Ragnar Lothbrok is described as interrogating people by tearing out one eye before asking any questions, then threatening the other. Shef has one of his eyes burned out with a red-hot needle.
- Historical Domain Character: Ragnar and the Ragnarssons, assorted kings.
- Magic Realism: Occasionally characters will have visions of the gods or the Other World, and sometimes see each other in those visions. Otherwise everything is grim, gritty realism. Also trolls.
- Named Weapons: Brand's axe Battle-Troll, Shef's halberd Thrall's-Wreak, Cwicca and Osmod's ballista Dead Level, Erkenbert's trebuchet War-Wolf, and others.
- One-Man Industrial Revolution: Shef has shades of this; while many of the inventions aren't his, he is the driving force behind the wave of new mechanisms and devices that sweep the world.
- Public Domain Artifact:
- The Lance of Longinus is a driving MacGuffin for the second book, as is Gungnir, the spear of Odin. They're actually the same spear, or "a good spear that conquers." Bruno ends up with it, though, and uses the legitimacy it gives him to become Holy Roman Emperor.
- The Holy Grailnote is used in the third book to carry away Shef.
- The Red Baron: Many significant characters: Viganote -Brandnote , Ragnar Lothbroknote , Sigurd Snakeeye, Ivar the Boneless. Shef eventually earns the title "The Victorious", while King Alfred is called "The Gracious".
- Red Herring: In The Hammer and the Cross, the Norse priests are certain that Shef has one of the gods as his patron. He's got one eye. He's got an instinctive grasp of military strategy and tactics, and the ruthlessness to carry them out. He quests after knowledge, at one point hanging from Yggdrasil in a vision. Clearly, it's Odin, right? Nope. It's Heimdall in his guise of Rig.
- Spell My Name with an "S": The covers usually use "Odin" because the name is more familiar and the "eth" rune is conventionally transliterated to "d", but in the narration, we get Othin.
- They Call Him "Sword": Brand's name means sword in Norse. His favored weapon is the axe, though.
- Well-Intentioned Extremist: When the narration looks in on Pope Innocent's thoughts, they're about how, for the sake of the meek who the Church was made to protect, he had to ruthlessly pursue worldly power. We don't see much of the "protecting the meek" part, though.