Dorian Hawkmoon von Köln is one of the aspects of the Eternal Champion, a library of books by Michael Moorcock consisting of many series. He's the duke of Köln in a Europe so far into the future that the geography is just about the only thing recognizable to someone of our era. Hawkmoon fights alongside Count Brass against the iniquity of Granbretan, the Dark Empire.
Although Hawkmoon's world is somewhat fantastic, and midieval it contains some bizarre technologies.

As his story unfolds, Hawkmoon finds that he is the unwitting, sometimes unwilling, chosen champion of a powerful, and legendary artifact, the Runestaff by which the people in his world swear, although many don't believe it actually exists.

The Runestaff is the physical incarnation of divine balance, and Hawkmoon finds his destiny manipulated toward it's ends. Fortunately for him, it's ends are intertwined with his, the vanquishing of the Dark Empire and one of it's nobles, the evil Baron Meliadus...