Great cover by Gray Morrow

First in the "Runestaff" series, featuring Dorian Hawkmoon. Hawkmoon, late the Duke of Koln, fell under the power of the Runestaff, a mysterious artifact more ancient than time itself. His destiny, shaped by a vengeful oath sworn by the maddened Baron Meliadus of the Dark Empire, pitted Hawkmoon in battle against his own allies and forced him, by the Black Jewel embedded in his skull, to betray his heritage. From the descriptions of the Dark Empire ruled by Granbretan and a vastly changed Europe, one can speculate if this is an alternate-world fantasy or a far-future SF tale. The original 4 Hawkmoon books are my favorites by Moorcock, and I strongly recommend them.