Keeper of the King
By Nigel Bennett and P.N. Elrod, 1998

"In Gaul at the dawn of the Middle Ages, Lord Richard was his family's fighting man, its invincible champion--until some force twisted his blade from his hand. And then he met the Lady Sabra, who soothed his wounds, healed his pride--and turned him into a vampire under her tutelage. His new job: Keeper of the King of England. True to Sabra's wishes, the English king was keeping civilization alive. Richard's object in unlife: keep the king alive at all costs. But that was then--now it's the 1990s and Richard's job isn't over." (from Amazon.com)

Paperback Info: ISBN 067187862X, Baen Books (Available)

More by Nigel Bennett: His Father's Son