Wolf In Shadow by David Gemmell
It is three hundred years since the world toppled on its axis and civilisation was destroyed. In this savagely reshaped world ruled by brigands and war-makers, a rider seeks a lost city. Pursuing a dream to calm the violence in his soul, Jon Shannow, the brigand slayer, desires only peace. But from the Plague Lands emerges a fresh terror. The Lord of the Pit and his hellborn army seek to plunge mankind into a new demonic era. Seemingly invincible, they make a fatal mistake: they take Shannow's woman for blood sacrifice. And find themselves facing the deadliest warrior of the new age. Jon Shannow - the Jerusalem Man.