Styrbiorn the Strong follows the life of a Swedish prince who seeks to reclaim his birthright through conquest and alliance. The narrative tracks Styrbiorn's transition from an exiled youth to a formidable warrior-king, navigating the complex political landscape of the Viking Age. He faces opposition from his own kin and rival chieftains, forcing him to rely on his martial prowess and strategic alliances to secure his throne. The story utilizes a formal, archaic prose style that emphasizes the legendary quality of the protagonist's life and the harsh realities of Northern European power struggles.

This work is often regarded as a stylistic departure from the author's more fantastical creations, grounding itself instead in the gritty reality of historical legend. Readers typically note the dense, rhythmic quality of the prose, which mirrors the sagas of old and demands a patient reading pace. The narrative is frequently praised for its commitment to period authenticity and its refusal to soften the brutal nature of the Viking era. It remains a significant, if niche, entry in the author's bibliography, appealing to those who appreciate the intersection of historical research and literary artifice.