Ice Prophet Series by William R. Forstchen

For millennia after the Accident, Earths small population was ravaged by plague and bloody wars. Then suddenly a leader emerged, offering the promise of renewal to an otherwise miserable world. But nothing was quite as it seemed.

His enemies had pinpointed the Prophet's weakness -- but exploiting it might destroy them all.Michael Ormson -- the Prophet -- revolutionized icewar, and his ramfleets destroyed armadas that had terrorized the frozen seas for two thousand years.The Cornathian Brotherhoods knew they must act soon against Michael, for his forces grew more powerful each day, and the enlightened message his agents were spreading could only lead to revolt... moreHis enemies had pinpointed the Prophet's weakness -- but exploiting it might destroy them all.Michael Ormson -- the Prophet -- revolutionized icewar, and his ramfleets destroyed armadas that had terrorized the frozen seas for two thousand years.The Cornathian Brotherhoods knew they must act soon against Michael, for his forces grew more powerful each day, and the enlightened message his agents were spreading could only lead to revolt.But Ormson lived in an impregnable fortress on a small island guarded by awesome fleets, fanatical armies, and diabolical ice traps. Somehow the brotherhoods would have to lure him onto the ice -- and provoke his wrath so that he would chase them. less

Although Michael Ormson, known as the Ice Prophet, and his forces have captured Cornath's capital, the world faces continued dark ages unless he can consolidate his power and escape the attacks of his enemies